Control Technology Research Articles

Characterization of three novel stem rot pathogens and their antagonistic endophytic bacteria associated with Cistanche deserticola.

Cistanche deserticola is a precious Chinese medicinal material with extremely high health care and medicinal value. In recent years, the frequent occurrence of stem rot has led to reduced or even no harvests of C. deserticola. The unstandardized use of farm chemicals in the prevention and control processes has resulted in excessive chemical residues, threatening the fragile desert ecological environment. Therefore, it is urgent to explore safe and efficient prevention and control technologies. Biocontrol agents, with the advantages of safety and environment-friendliness, would be an important idea. The isolation, screening and identification of pathogens and antagonistic endophytic bacteria are always the primary basis. In this study, three novel pathogens causing C. deserticola stem rot were isolated, identified and pathogenicity tested, namely Fusarium solani CPF1, F. proliferatum CPF2, and F. oxysporum CPF3. For the first time, the endophytic bacteria in C. deserticola were isolated and identified, of which 37 strains were obtained. Through dual culture assay, evaluation experiment and tissue culture verification, a biocontrol candidate strain Bacillus atrophaeus CE6 with outstanding control effect on the stem rot was screened out. In the tissue culture system, CE6 showed excellent control effect against F. solani and F. oxysporum, with the control efficacies reaching 97.2% and 95.8%, respectively, indicating its great potential for application in the production. This study is of great significance for the biocontrol of plant stem rot and improvement of the yield and quality of C. deserticola.

High aspect ratio Na–Co-oxide ceramic filler composites with novel electrical and dielectric properties

Polymer composites with high aspect ratio Na–Co oxide ceramic filler – polymer matrix was investigated in this study. They demonstrate high dielectric permittivity, low dielectric loss tangent values which is useful for capacitive field grading and reversible voltage dependent electrical conductivity properties under an applied electric field which can be utilized for resistive field grading. These unique properties are useful for electrical stress control applications in power components. This study employs novel ceramic platelets as the varistor filler component in a polymer composite form, introducing a new class of materials to the world of electrical stress control technology. By minimizing the amount of varistor filler material required to very low levels (15 wt%), it is possible to develop lightweight non-linear dielectric composites that not only exhibit improved electrical characteristics but also make processing easier and open up new design space for making various components for electrical power applications. By utilizing novel NaxCoO2 (x < 1) ceramic fillers in composite form, we aim to contribute to the development of innovative nonlinear dielectric composites that can enhance the performance and processibility of various power system components under various working environments.

A hybrid sensory feedback system for thermal nociceptive warning and protection in prosthetic hand.

Advanced prosthetic hands may embed nanosensors and microelectronics in their cosmetic skin. Heat influx may cause damage to these delicate structures. Protecting the integrity of the prosthetic hand becomes critical and necessary to ensure sustainable function. This study aims to mimic the sensorimotor control strategy of the human hand in perceiving nociceptive stimuli and triggering self-protective mechanisms and to investigate how similar neuromorphic mechanisms implemented in prosthetic hand can allow amputees to both volitionally release a hot object upon a nociceptive warning and achieve reinforced release via a bionic withdrawal reflex. A steady-state temperature prediction algorithm was proposed to shorten the long response time of a thermosensitive temperature sensor. A hybrid sensory strategy for transmitting force and a nociceptive temperature warning using transcutaneous electrical nerve stimulation based on evoked tactile sensations was designed to reconstruct the nociceptive sensory loop for amputees. A bionic withdrawal reflex using neuromorphic muscle control technology was used so that the prosthetic hand reflexively opened when a harmful temperature was detected. Four able-bodied subjects and two forearm amputees randomly grasped a tube at the different temperatures based on these strategies. The average prediction error of temperature prediction algorithm was 8.30 ± 6.00%. The average success rate of six subjects in perceiving force and nociceptive temperature warnings was 86.90 and 94.30%, respectively. Under the reinforcement control mode in Test 2, the median reaction time of all subjects was 1.39 s, which was significantly faster than the median reaction time of 1.93 s in Test 1, in which two able-bodied subjects and two amputees participated. Results demonstrated the effectiveness of the integration of nociceptive sensory strategy and withdrawal reflex control strategy in a closed loop and also showed that amputees restored the warning of nociceptive sensation while also being able to withdraw from thermal danger through both voluntary and reflexive protection. This study demonstrated that it is feasible to restore the sensorimotor ability of amputees to warn and react against thermal nociceptive stimuli. Results further showed that the voluntary release and withdrawal reflex can work together to reinforce heat protection. Nevertheless, fusing voluntary and reflex functions for prosthetic performance in activities of daily living awaits a more cogent strategy in sensorimotor control.

System design and clinical validation of intelligent nucleic acid POCT for un SARS-CoV-2 detection within 30 min

Rapid and accurate point-of-care-test (POCT) allows us to substantially accelerate taking clinical decisions and implement strategic planning at the national level of preventative measures in epidemic prevention and control. Here, we report Intelligent Nucleic Acid Test (iNAT) for the RT-qPCR detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA with a limit of detection (LOD) of 22.4 copies/mL. iNAT is a sample-to-answer system consisting of an instrument and a fully enclosed detection chip containing reaction reagents, based on rotary valve liquid control technology, ultrasonic-assisted nucleic acid extraction (NAE) technology, thin-sheet rapid PCR technology, freeze-drying technology, liquid transfer, NAE and RT-qPCR are all completed automatically, quickly and efficiently, and free of cold chain transportation and storage. The user only needs to put the chip with 160 μL sample into the instrument and click to start, the test result will report after 30 min. In a clinical trial between the iNAT and the traditional RT-qPCR kits approved by National Medical Products Administration (NMPA), involving 158 throat swab samples, the concordance rate reached 96.2%, the positive percent agreement (PPA) is 95.8%, and the negative percent agreement (NPA) is 97.3%, the parallel analysis of Ct values of 115 positive samples was a high correlation (R2 = 0.95), 4 of 10 weak positive samples were missed by iNAT while 6 of 10 weak positive samples were missed by reference kits. In a word, iNAT system provide an ultra-high sensitivity and fast POCT detection method for SARS-CoV-2.

What comes around, goes around: how neo/normative control accidently enables its own resistance

PurposeThe paper discusses how the management of a sports and fashion company, which we refer to as NULMA, successfully applied the neo/normative control technology “karma organisation” and gained employee engagement. Whereas other studies have documented employee resistance to organisational cultures when used for managerial control, our case demonstrates resistance to management practices that employees find inconsistent with the dominant karma culture.Design/methodology/approachThe study is based on a six-year longitudinal organisational at-home ethnography conducted by one of the authors using methods of both participant and non-participant observation, semi-structured interviews and collaborative production of secondary data in the case organisation.FindingsWhile our research shows that management can successfully apply neo/normative control which employees accept and support, we further show that employees mobilise the same values to resist management when it fails to deliver on the commitments and promises of the organisational culture.Originality/valueThe study contributes to the literature on organisational culture and, in particular, neo/normative control by theorising employee resistance as being by “accident”, by which we mean an inherent negative potentiality co-invented and released by managers establishing a “karma organisation”. Our theorising culminates in a discussion of the study’s implications for research and practice.

Camera-based plant growth monitoring for automated plant cultivation with controlled environment agriculture

Building integrated photovoltaic thermal (BIPVT) greenhouse technology exhibits great potential to enhance crop yielding, energy harvesting, and water management for highly efficient farming and enables controlled environment agriculture (CEA) for automated plant cultivation. The proposed smart greenhouse system uses BIPVT, geothermal, image-based sensing, and control technologies for high energy efficiency and high-fidelity plant growth control. A camera-based, computer-controlled system was demonstrated to successfully monitor single and multiple food plants' growth. The growth rate over the life-cycle of the plant was automatically recorded by cameras without human interference. A novel algorithm was developed to extract the plants from the background of the image and then to measure the length from the ground to the top of the longest plant with different shapes or profiles. The growth rate was automatically generated as fundamental data for farming management and control. Because the plant growth is slow and the errors caused by image noise can be comparable with the actual growth when the interval between images is not large enough, the noise of a camera is evaluated by comparing multiple images under the same exposure condition, which is used to provide the error range of the measurements. The plant growth monitoring system will be integrated into an ongoing greenhouse project for smart greenhouse operation.

Voice Recognition Based Vital Parameter Monitoring Patient BED

In healthcare protocols continuous monitoring of vital parameters plays a crucial role in patient care. Integrating advanced technologies for both monitoring and patient comfort enhances the efficiency of healthcare delivery. This paper presents the design and development of a novel patient bed system equipped with vital parameter monitoring capabilities and adjustable head position controlled through voice commands. The proposed system leverages state-of-the-art sensors to monitor vital parameters such as heart rate, blood pressure, oxygen saturation, and temperature. These sensors are seamlessly integrated into the bed, providing non-intrusive and continuous monitoring of the patient's health status. Real-time data acquisition and processing algorithms ensure accurate and timely assessment of the patient's condition. Furthermore, the patient bed is designed with an adjustable head position feature, allowing for optimal comfort and support. Unlike conventional manual or automated adjustment mechanisms, our system employs voice control technology for intuitive and hands-free operation. Patients can simply issue verbal commands to adjust the head position according to their preferences, enhancing overall comfort and facilitating better rest.

A quanta-independent approach for the assessment of strategies to reduce the risk of airborne infection

The Wells-Riley model is extensively used for retrospective and prospective modelling of the risk of airborne transmission of infection in indoor spaces. It is also used when examining the efficacy of various removal and deactivation methods for airborne infectious aerosols in the indoor environment, which is crucial when selecting the most effective infection control technologies. The problem is that the large variation in viral load between individuals makes the Wells-Riley model output very sensitive to the input parameters and may yield a flawed prediction of risk. The absolute infection risk estimated with this model can range from nearly 0 % to 100 % depending on the viral load, even when all other factors, such as removal mechanisms and room geometry, remain unchanged. We therefore propose a novel method that removes this sensitivity to viral load. We define a quanta-independent maximum absolute before-after difference in infection risk that is independent of quanta factors like viral load, physical activity, or the dose-response relationships. The input data needed for a non-steady-state calculation are just the removal rates, room volume, and occupancy duration. Under steady-state conditions the approach provides an elegant solution that is only dependent on removal mechanisms before and after applying infection control measures. We applied this method to compare the impact of relative humidity, ventilation rate and its effectiveness, filtering efficiency, and the use of ultraviolet germicidal irradiation on the infection risk. The results demonstrate that the method provides a comprehensive understanding of the impact of infection control strategies on the risk of airborne infection, enabling rational decisions to be made regarding the most effective strategies in a specific context. The proposed method thus provides a practical tool for mitigation of airborne infection risk.

Design of a focusing system for micro-nano satellite remote sensing camera based on thermal control technology

Remote sensing cameras mounted on micro-nano satellite mare susceptible to optical system defocusing during launch and operation due to environmental influences. Traditional focusing system encounter issues such as large volume and mass, making them unsuitable for the design requirements of micro-nano satellite. Proposes a thermal control-based focusing system for compact systems with maintained imaging quality. The design is developed according to the characteristics of a compact coaxial four-mirror remote sensing camera optical system and the overall structure of the system. The focusing system utilizes structural thermal expansion to alter the distance between the primary and secondary mirrors, achieving the purpose of adjusting the system’s focal length. Finite element simulations were conducted to analyze the modal and thermal deformations of the overall structure, validating the rationality of the system design. Experimental verification of the thermal control focusing system demonstrated its adjustment accuracy and range, with clear imaging obtained after system focusing. The results indicate that when the temperature control accuracy reaches ±0.5 °C, the focal length adjustment accuracy can reach 0.0052 mm. This article proposed thermal control focusing system can adjust the camera’s focal length in orbit, exhibiting advantages such as a small volume, high stiffness, and high precision.

A systematic approach for threat and vulnerability analysis of unmanned aerial vehicles

The proliferation of Unmanned Aerial Vehicles (UAVs) is expected to experience a substantial rise in the next years, driven by their ever-increasing application across various domains. However, ensuring secure communication between UAVs and their ground stations is crucial to prevent the unauthorized disclosure of sensitive information that could jeopardize the mission’s integrity when exploited by malicious actors. Despite this importance, several UAV systems currently operate based on open-source command and control technologies, which have overlooked several security considerations while focusing on availability and safety. To address this concern, this study conducts a comprehensive security assessment of UAV-based systems starting with a systematic literature review whose main purpose is building a comprehensive catalog of threats associated with this technology. Particular attention has been paid to the MAVlink protocol, an open-source protocol commonly utilized for telemetry and command and control for multiple UAVs. Therefore, drawing upon the built catalog, a threat modeling and penetration testing technique has been employed to examine the MAVlink implementation on a real UAV. A threat model developed for a specific case study is also presented, leading to the discovery of four new vulnerabilities, some of which were successfully exploited through attacks. By shedding light on these vulnerabilities, this work seeks to encourage further investigation and research to develop robust security mechanisms for UAV communication systems. It is imperative to address these vulnerabilities proactively to enhance the overall security posture and safeguard against potential threats in the UAV ecosystem.

A smartphone-based diagnostic analyzer for point-of-care milk somatic cell counting

BackgroundMastitis, a pervasive and detrimental disease in dairy farming, poses a significant challenge to the global dairy industry. Monitoring the milk somatic cell count (SCC) is vital for assessing the incidence of mastitis and the quality of raw cow's milk. However, existing SCC detection methods typically require large-scale instruments and specialized operators, limiting their application in resource-constrained settings such as dairy farms and small-scale labs. To address these limitations, this study introduces a novel, smartphone-based, on-site SCC testing method that leverages smartphone capabilities for milk somatic cell identification and enumeration, offering a portable and user-friendly testing platform. ResultsThe central findings of our study demonstrate the effectiveness of the proposed method for counting milk somatic cells. Its on-site applicability, facilitated by the microfluidic chip, optical system, and smartphone integration, heralds a paradigm shift in point-of-care testing (POCT) for dairy farms and smaller laboratories. This approach bypasses complex processing and presents a user-friendly solution for real-time SCC monitoring in resource-limited settings. This device boasts several unique features: small size, low cost (<$1,000 total manufacturing cost and <$1 per test), and high accuracy. Remarkably, it delivers test results within just 2 min. Actual-sample testing confirmed its consistency with results from the commercial Bentley FTS/FCM cytometer, affirming the reliability of the proposed method. Overall, these results underscore the potential for transformative change in dairy farm management and laboratory testing practices. SignificanceIn summary, this study concludes that the proposed smartphone-based method significantly contributes to the accessibility and ease of SCC testing in resource-limited environments. By fostering the use of POCT technology in food safety control, particularly in the dairy industry, this innovative approach has the potential to revolutionize the monitoring and management of mastitis, ultimately benefiting the global dairy sector.

Research on Energy Storage Flywheel Motor Drive Control Technology

Currently there is a way to use for energy storage: batteries for chemical energy storage, super for electric field energy storage, and flywheel batteries for mechanical energy storage. Flywheel energy storage has the advantages of high energy storage density, high efficiency, short charging time, no pollution, wide applicability, no noise, long service life, easy maintenance and continuous operation. Recently the most promising and competitive new energy storage technology - flywheel energy storage technology, relative to other forms of energy storage, by domestic and foreign experts unanimously optimistic. This paper will focus on the composition and operation principle of flywheel energy storage system, the classification of drive control strategy, charging control strategy, discharge control strategy and other aspects.

Study on Illuminance Control based on Arduino Method

The paper presents a method for achieving constant illumination control by integrating various technologies, including Arduino technology, LED driver technology, and control technology. The HV9910B constant current drive chip is used to design a high-power LED driver in the form of an Arduino expansion board. The performance of the driver is tested, including efficiency testing and waveform testing. The PID control library of Arduino is utilized to write the control program rapidly. Illumination control experiments are conducted with expected results.

Gas control technology for coal and gas outburst mines based on new sealing materials

In order to solve the problem of gas overlimit in corner corners of coal and gas prominent mines, through the combination of air leakage mechanism in the goaf, near-field fissure expansion and rich area division, blocking material development and optimization, performance measurement of blocking materials and on-site test, we started to study the causes of gas concentration in corner corners, analysis of roof collapse and transparency in corners and performance test of blocking materials, and optimized the blocking materials by combining laboratory test and engineering test. Considering the thickness of the sealing film, the attenuation ratio of the sealing film thickness, the gelation time, and the gelation viscosity under different ratios, designing a multi factor orthogonal experiment to optimize the optimal ratio suitable for the engineering site. Factors affecting blocking effectiveness, such as gel water retention and gel flame resistance, were also tested. The sealing scheme was implemented in the 2109 working face of a coal and gas outburst mine in Gansu, China. Through on-site monitoring of the changes in temperature, gas concentration, and air leakage at each monitoring point before and after the use of sealing materials, the analysis of the detection results shows that the temperature changes at each monitoring point after the use of sealing materials do not exceed 0.2 °C; The change in oxygen concentration is less than 0.27%; The gas concentration has decreased by more than 60%, with a decrease of 71.32% in the gas concentration in the upper corner. The air leakage has decreased by more than 53%, the proportion of decrease in air leakage at the upper corner is as high as 56.83%. This air leakage control technology has remarkable blocking effect, meets the requirements of corner near-field fissure blocking material, and is easy to prepare, inexpensive, non-toxic, tasteless and green, providing a successful experience for the treatment of similar coal and gas outburst mines that can be referenced.

Aerodynamic/control integrated optimization method for unpowered high-speed vehicle configuration design

The unpowered high-speed vehicle experiences a significant coupling between the disciplines of aerodynamics and control due to its characteristics of high flight speed and extensive maneuverability within large airspace. The conventional aircraft conceptual design process follows a sequential design approach, and there is an artificial separation between the disciplines of aerodynamics and control, neglecting the coupling effects arising from their interaction. As a result, this design process often requires extensive iterations over long periods when applied to high-speed vehicles, and may not be able to effectively achieve the desired design objectives. To enhance the overall performance and design efficiency of high-speed vehicles, this study integrates the concept of Active Control Technology (ACT) from modern aircraft into the philosophy of aerodynamic/control integrated optimization. Two integrated optimization strategies, with differences in coupling granularity, have been developed. Subsequently, these strategies are put into action on a biconical vehicle that operates at Mach 5. The results reveal that the comprehensive performance of the synthesis optimal model derived from the aerodynamic/control integrated optimization strategy is improved by 31.76% and 28.29% respectively compared to the base model under high-speed conditions, demonstrating the feasibility and effectiveness of the method and optimization strategies employed. Moreover, in comparison to the single-stage strategy, the multi-stage strategy takes into deeper consideration the impact of control capacity. As a result, the control performance of the synthesis optimal model derived from the multi-stage strategy improves by 13.99%, whereas the single-stage strategy only achieves a 5.79% improvement. This method enables a fruitful interaction between aerodynamic configuration design and control system design, leading to enhanced overall performance and design efficiency. Furthermore, it improves the controllability of high-speed vehicles, mitigating the risk of mission failure resulting from an ineffective control system.

High-Speed Controller to Enhance Responsiveness and Stability of Dynamic Characteristics for DC–DC Converter

In general, the DC load is electrically sensitive to the input voltage and current compared to the AC load. As the demand for digital systems that require DC power increases rapidly, the importance of stable DC power supply methods is increasing. Various elements such as renewable energy and load are configured in the power grid that supplies DC, and they are connected in various forms and power patterns. These elements have different starting and operating characteristics, which can be disadvantageous to the design of controllers for power converters to maintain a stable bus voltage in the DC power grid. Therefore, in a DC power system, an energy storage system with active bi-directional power control technology that can minimize transient conditions, such as overshoot, which can occur when a load is connected or power accelerates rapidly, is significantly important. This paper proposes a novel power control method capable of compensating for the instability of the DC bus voltage owing to the transient state in the DC power supply system. This method minimizes overshoot and ensures fast responsiveness and system stability by calculating the flux linkage of an inductor in a bi-directional DC/DC converter and applying an excitation voltage without pulse-width modulation (PWM) switching. The performance and validity of the proposed transient high-speed controller (THSC) were verified through simulations and experiments.

Distributed active vibration control for helicopter based on diffusion collaboration

The active vibration control technology has been successfully applied to several helicopter types. However, with the increasing of control scale, traditional centralized control algorithms are experiencing significant increase of computational complexity and physical implementation challenging. To address this issue, a diffusion collaboration-based distributed Filtered-x Least Mean Square algorithm applied to active vibration control is proposed, drawing inspiration from the concept of data fusion in wireless sensor network. This algorithm distributes the computation load to each node, and constructs the active vibration control network topology of large-scale system by discarding the weak coupling secondary paths between nodes, achieving distributed active vibration control. In order to thoroughly validate the effectiveness and superiority of this algorithm, a helicopter fuselage model is designed as the research object. Firstly, the excellent vibration reduction performance of the proposed algorithm is confirmed through simulations. Subsequently, specialized node control units are developed, which utilize STM32 microcontroller as the processing unit. Further, a distributed control system is constructed based on multi-processor collaboration. Building on this foundation, a large-scale active vibration control experimental platform is established. Based on the platform, experiments are carried out, involving the 4-input 4-output system and the 8-input 8-output system. The experimental results demonstrate that under steady-state harmonic excitation, the proposed algorithm not only ensures control effectiveness but also reduces computational complexity by 50%, exhibiting faster convergence speed compared with traditional centralized algorithms. Under time-varying external excitation, the proposed algorithm demonstrates rapid tracking of vibration changes, with vibration amplitudes at all controlled points declining by over 94%, proving the strong robustness and adaptive capability of the algorithm.

Investigation of control effects of end-wall self-adaptive jet on three-dimensional corner separation of a highly loaded compressor cascade

To overcome the limitations posed by three-dimensional corner separation, this paper proposes a novel flow control technology known as passive End-Wall (EW) self-adaptive jet. Two single EW slotted schemes (EWS1 and EWS2), alongside a combined (COM) scheme featuring double EW slots, were investigated. The results reveal that the EW slot, driven by pressure differentials between the pressure and suction sides, can generate an adaptive jet with escalating velocity as the operational load increases. This high-speed jet effectively re-excites the local low-energy fluid, thereby mitigating the corner separation. Notably, the EWS1 slot, positioned near the blade leading edge, exhibits relatively low jet velocities at negative incidence angles, causing jet separation and exacerbating the corner separation. Besides, the EWS2 slot is close to the blade trailing edge, resulting in massive low-energy fluid accumulating and separating before the slot outlet at positive incidence angles. In contrast, the COM scheme emerges as the most effective solution for comprehensive corner separation control. It can significantly reduce the total pressure loss and improve the static pressure coefficient for the ORI blade at 0°-4° incidence angles, while causing minimal negative impact on the aerodynamic performance at negative incidence angles. Therefore, the corner stall is delayed, and the available incidence angle range is broadened from −10°–−2° to −10°–4°.This holds substantial promise for advancing the aerodynamic performance, operational stability, and load capacity of future highly loaded compressors.

Finite-Time Adaptive Fuzzy Backstepping Control for Quadrotor UAV With Stochastic Disturbance

This paper proposes an adaptive fuzzy output feedback control approach for quadrotor unmanned aerial vehicles (QUAV) with stochastic disturbances, besides which we consider the unmeasurable states and unknown nonlinear functions. The QUAV system contains stochastic terms which are not bounded and not differentiable. By combining the It <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\hat{\rm \textbf{o}}$</tex-math> </inline-formula> differential equation with finite-time theory, a novel stochastic finite-time stability controller for QUAV is raised for the first time. The fuzzy logic system (FLS) is utilized to approximate the unknown nonlinear functions in the model. Dynamic surface control technology is introduced to reduce the complexity of differential. Furthermore, an observer with FLS is designed through the adaptive backstepping technique to estimate the immeasurable states. It is proved that this control approach can ensure that all states of the closed-loop QUAV system are semi-global and finite-time stable in probability. Meanwhile, the errors of system outputs and observer converge to a small neighborhood of origin. The simulation results show the effectiveness of the proposed method. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —In practical applications, many systems are often affected by internal and external disturbances, and not all of them can be described by mathematical models, so they are called stochastic disturbances. Taking the QUAV as an example, when the system is disturbed by internal parameters, external environment, system input, sensor error, and other stochastic factors, the deterministic system can no longer accurately describe the controlled object. In this paper, the QUAV is regarded as a stochastic system for the first time, and a novel controller is designed to solve the above problems. In addition, the QUAV needs fast action in some applications, such as emergency collision avoidance, which has high requirements for the convergence performance of the controller. Therefore, studying the finite-time control for QUAV systems with stochastic disturbances is necessary. At the same time, this paper also considers the problem that the state is not measurable and the system contains unknown nonlinear equations.

Off-line location strategy for single-phase ground fault of distribution line

This paper adopts off-line location strategy of single-phase grounding fault of distribution lines, determines size and frequency of injected AC signal by analyzing distribution parameters of lines, and then develops portable small current signal source with adjustable frequency through power conversion control technology, and develops signal detector by analyzing noise correlation and adaptive morphological filtering. Then off-line location strategy is developed according to above two signal devices. Finally, it is verified that the strategy can accurately locate fault point of distribution line.