Propulsion Control System Research Articles

An H ∞ H - optimization approach to fault detection for UAV

Unmanned aerial vehicles (UAVs) have good maneuverability and have been widely used in many fields. Therefore, it is of great significance to detect faults in the UAV flight control system. In this paper, a method based on H ∞ H - optimization is proposed for the constant gain fault detection of UAV flight control system actuators, and the failure of UAV elevator and throttle lever parts are used as the example for simulation verification. The results show that the proposed method can realize the quick fault detection of UAV flight control system.

기계식 추진 시스템 제어를 위한 가스터빈 엔진 모델링 및 시뮬레이션

기계식 추진 시스템 제어를 위한 가스터빈 엔진 모델링 및 시뮬레이션

Design and Development of DALBIT-1: Earth-Based Lander Test Bed

DALBIT-1, a miniature-sized, fully integrated, Earth-based lander test bed was designed and developed for the vertical takeoff and vertical landing flight demonstration. Mission and design requirements and vehicle subsystems were selected to accommodate the vertical takeoff and vertical landing preliminary flight demonstration. Subsystems, including the propulsion system, structure, avionics, and ground control station, were designed, developed, and integrated as a system. The flight control system of DALBIT-1 was generated to enable the vehicle an autonomous flight and was validated using a computer simulation in a MATLAB/Simulink environment. Simulation results show that DALBIT-1 adequately follows the predetermined trajectory and softly lands on the surface. The developed test bed performed a series of static fire tests and water/propellant flow tests to enhance the predictability of the flight control system. Using the developed flight control system, finally, the preliminary flight demonstration was conducted and proved the capability of the test bed of performing a vertical liftoff, vertical landing flight.

A novel decision support methodology for oceangoing vessel collision avoidance

The wider use of electronic devices in shipping has led to the introduction of new navigation control systems and decision support tools for collision avoidance. The application of these systems improves the data utilisation and allows for the prediction of ship's performance in various operational conditions. In this study, a decision support methodology for collision avoidance of ocean going vessels is developed, taking into account both the ship's manoeuvrability and propulsion system performance whilst employing a new formulation for the estimation of the collision probability indicator. An integrated model that simulates the ship's manoeuvrability and propulsion system performance is employed to predict the required ship's hull and propulsion plant dynamic response. The integrated model couples a 3-DOF manoeuvring model with a mean value engine model, providing a fast but accurate prediction of ship and her propulsion system characteristics during specific manoeuvring scenarios. The derived ship trajectories populate a database that is employed as input to the developed decision support for investigating various encounter situations depending on the target ship's initial position, approach angle, trajectory and speed. The developed decision support provides the collision probability indicator as function of the ordered rudder angle and engine speed as the available control options to avoid the collision. This study provides support to the officer of the watch to make decisions on the ship and propulsion system control parameters during encountering situations, thus contributing to the safer maritime operations.

Sensing and Control of a Multi-Joint Soft Wearable Robot for Upper-Limb Assistance and Rehabilitation

In the field of wearable robotics, there has been increased interest in the creation of soft wearable robots to provide assistance and rehabilitation for those with physical impairments. Compared to traditional robots, these devices have the potential to be fully portable and lightweight, a flexibility that may allow for increased utilization time as well as enable use outside of a clinical environment. In this letter, we present a textile-based multi-joint soft wearable robot to assist the upper limb, in particular shoulder elevation and elbow extension. Before developing a portable fluidic supply system, we leverage an off-board actuation system for power and control, with the worn components weighting less than half kilogram. We showed that this robot can be mechanically transparent when powered off, not restricting users from performing movements associated with activities of daily living. Three IMUs were placed on the torso, upper arm and forearm to measure the shoulder and elbow kinematics. We found an average RMSE of ~ 5 degrees when compared to an optical motion capture system. We implemented dynamic Gravity Compensation (GC) and Joint Trajectory Tracking (JTT) controllers that actively modulated actuator pressure in response to IMU readings. The controller performances were evaluated in a study with eight healthy individuals. Using the GC controller, subject shoulder muscle activity decreased with increasing magnitude of assistance and for the JTT controller, we obtained low tracking errors (mean ~ 6 degrees RMSE). Future work will evaluate the potential of the robot to assist with activities in post-stroke rehabilitation.

Control of the Test Rig for Spring Stiffness Measurement with Hydraulic Integrated Actuator and Computer Vision

The paper deals with the control of the test rig for measurement of the stiffness of the spring. The test rig is equipped with integrated hydraulic actuator and multilayer control system with computer vision to automate the testing process and to increase the safety of the operating staff during the testing. The integrated hydraulic actuator allows to control the piston velocity and position and to produce the force needed for the spring compression and stiffness measurement. It has an integrated manifold with four proportional flow control valves connected as the full hydraulic resistance bridge. Each control valve is controlled separately using the input signal. That makes it possible to realize different connections and control strategies of the hydraulic cylinder using the different control algorithms. The hydraulic circuit was modelled and simulated, and the achieved simulation results are presented in the paper. The test rig is controlled using the microprocessor control system and is it equipped by different transducers – position transducer, pressure transducers and force transducer to be able to collect data important for the stiffness characteristic evaluation. The upper level of the control system is created by the vision control system. The goal of the implementation of the machine vision is to decrease the number of the manual operations done by the technician by the spring testing and to extend the automatic testing cycle of the automatic computer vision-controlled movement of the actuator at the beginning of the testing cycle and finally to increase the safety of the operating staff. The structure and functionality of the designed control system, experimentally obtained results and evaluated stiffness characteristic of the tested spring are presented in the following chapters.

Development of a Methodology Using Artificial Neural Network in the Detection and Diagnosis of Faults for Pneumatic Control Valves.

To satisfy the market, competition in the industrial sector aims for productivity and safety in industrial plant control systems. The appearance of a fault can compromise the system’s proper functioning process. Therefore, Fault Detection and Diagnosis (FDD) methods contribute to avoiding any undesired events, as there are techniques and methods that study the detection, isolation, identification and, consequently, fault diagnosis. In this work, a new methodology that uses faults emulation to obtain parameters similar to the Development and Application of Methods for Diagnosis of Actuators in Industrial Control Systems (DAMADICS) benchmark model will be developed. This methodology uses previous information from tests on sensors with and without faults to detect and classify the situation of the plant and, in the presence of faults, perform the diagnosis through a process of elimination in a hierarchical manner. In this way, the definition of residue signature is used as well as the creation of a decision tree. The whole process is carried out incorporating FDD techniques, through the Non-Linear Auto-Regressive Neural Network Model With Exogenous Inputs (NARX), in the diagnosis of the behavioral prediction of the signals to generate the residual values. Then, it is applied to the construction of the decision tree based on the most significant residue of a certain signal, enabling the process of acquisition and formation of the signature matrix. With the procedures in this article, it is possible to demonstrate a practical and systematic method of how to emulate faults for control valves and the possibility of carrying out an analysis of the data to acquire signatures of the fault behavior. Finally, simulations resulting from the most sensitized variables for the production of residuals that is generated by neural networks are presented, which are used to obtain signatures and isolate the flaws. The process proves to be efficient in computational time and makes it easy to present a fault diagnosis strategy that can be reproduced in other processes.

Independent position control of two identical magnetic microrobots in a plane using rotating permanent magnets

Microrobots are attracting a lot of interest due to their numerous applications including micro-manipulation and targeted drug delivery. A major challenge in microrobotics is the control of multiple microrobots independently, especially identical microrobots. This paper proposes a novel actuation system for simultaneous planar position control of two identical magnetic microrobots. Four rotating permanent magnets are used to produce the desired magnetic field and consequently desired magnetic force. Angles of the permanent magnets are found analytically by PI control strategy to produce desired forces on microrobots. Microrobots move adequately far apart, so the interaction forces between microrobots can be neglected in comparison to the forces exerted on microrobots by rotating permanent magnets. The conducted simulations demonstrate the capability of the proposed system to control the position of two microrobots independently. Additionally, an experiment is performed to verify the capability of the proposed approach. Moving microrobots in the opposite and same directions and moving one microrobot to the desired position while keeping the other one stationary are illustrated in the experiment. Finally, the limitations of the presented system are discussed.

The Effect of Attack Angle On The Vibration Suppression Of Composite Wing Airfoil NACA 0012

Active vibration control is presented as an effective technique used for vibration suppression and for attenuating bad effects of disturbances on structure. In this work Proportional-Integral-Derivative control were employed to study suppression of active vibration wing affected by wind airflow. Two different composite wings with different manufacturing materials had been made with specific size to be suitable for using in wind tunnel. Piezoelectric (PZT (transducers are used as sensors and actuators in vibration control systems. The velocity was 25 m/s and three different attack angles (0, 10, 20 degrees) had been taken to show their effect on the wings vibrations suppression. The results shows that the suppression of the wing amplitude is reduced when the attack angle increases for both woven and random composite wing matt and this happened due to the vortex which became more violent at the increase of attack angle and also due to the area that face the wind which will increase when the attack angle increase and this will reduces the suppression. The maximum control amplitude of woven Glass-fiber matt was 1.75cm and the damping was about 38 % at zero attack angle while it was 2cm and the damping was about 26 % at 20 degree attack angle for random Glass-fiber composite matt

The Effect of Attack Angle On The Vibration Suppression Of Composite Wing Airfoil NACA 0012

Active vibration control is presented as an effective technique used for vibration suppression and for attenuating bad effects of disturbances on structure. In this work Proportional-Integral-Derivative control were employed to study suppression of active vibration wing affected by wind airflow. Two different composite wings with different manufacturing materials had been made with specific size to be suitable for using in wind tunnel. Piezoelectric (PZT (transducers are used as sensors and actuators in vibration control systems. The velocity was 25 m/s and three different attack angles (0, 10, 20 degrees) had been taken to show their effect on the wings vibrations suppression. The results shows that the suppression of the wing amplitude is reduced when the attack angle increases for both woven and random composite wing matt and this happened due to the vortex which became more violent at the increase of attack angle and also due to the area that face the wind which will increase when the attack angle increase and this will reduces the suppression. The maximum control amplitude of woven Glass-fiber matt was 1.75cm and the damping was about 38 % at zero attack angle while it was 2cm and the damping was about 26 % at 20 degree attack angle for random Glass-fiber composite matt

ОПТИМАЛЬНЕ КЕРУВАННЯ СУДНОВИМИ КОМБІНОВАНИМИ ПРОПУЛЬСИВНИМИ КОМПЛЕКСАМИ

Стаття присвячена розв’язанню задачі оптимального керування судновими комбінованими пропульсивними комплексами з диференційними привод-генераторними агрегатами з метою підвищення їх ефективності. У роботі виконано аналіз структури суднового пропульсивного комплекса як гідромеханічної системи, що включає корпус судна і пропульсивну установку, в якій енергія робочого тіла перетворюється в упор, що приводить в рух корпус судна, обґрунтовано перспективність впровадження комбінованих пропульсивних комплексів, в яких застосовуються кілька різнотипних двигунів, що працюють на один або кілька рушіїв. Розглянуто математичну модель процесу керування судновим комбінованим пропульсивним комплексом, що дозволяє проводити аналіз роботи валогенераторної установки з диференційним привод-генераторним агрегатом, як при ходовому, так і при аварійному режимі функціонування. Формалізовано завдання керування судновими комбінованими пропульсивними комплексами на основі критерія узагальненої оцінки якості їх функціонування, що враховує відхилення ходового навантаження пропульсивного комплексу при обмеженнях щодо відхилення потужності бортової мережі від бажаної та сформульовано задачу оптимального керування судновими комбінованими пропульсивними комплексами за мінімумом відхилень механічної потужності при обмеженнях щодо забезпечення живлення споживачів. Запропоновано новий метод оптимального керування частотним перетворювачем генератора опори, що забезпечує мінімізацію визначеного критерію із дотриманням відповідних обмежень. Алгоритм оптимального керування комбінованого пропульсивного комплекса включає: етапи аналізу значень заданої та діючої механічної потужності на гвинті судна; визначення електричної потужності, що виробляється допоміжною енергетичною установкою судна та споживаної у відповідному режимі; обчислення керування перетворювачем частоти, що забезпечує за рахунок підтримання відповідної потужності генератора опори мінімум відхилення потужності на гвинті при забезпеченні необхідного енергетичного балансу електромережі судна. Враховуючи випадковий характер навантажень, як з боку електричної енергосистеми, так і безпосередньо рухової установки, що ускладнює реалізацію представленого алгоритму оптимального управління в реальному часі, обґрунтовано доцільність застосування нечітких алгоритмів для підвищення ефективності процесів керування. Отримані результати можуть бути використані при побудові високоефективних систем керування судновими комбінованими пропульсивними комплексами для покращення якісних показників електричної енергії в судновій енергетичній системі та забезпечення працездатність суднової енергосистеми при аварійних ситуаціях. Ключові слова: математична модель, судновий пропульсивний комплекс, диференціальний привод, валогенератор, оптимальне керування, регулятор.

ПЕРСПЕКТИВЫ РАЗВИТИЯ ПРИВОДОВ РУЛЕВЫХ ПОВЕРХНОСТЕЙ ГРАЖДАНСКОГО САМОЛЕТА

The main problems arising in the development of systems of actuators with remote control for promising aircraft are considered. The tasks of the fly-by-wire control system for actuators of the aircraft are determined. The directions of development of improving the mass-dimensional and dynamic characteristics, improving the design and layout of circuit solutions, control systems and improving operational characteristics, which provide an increase in the quality and safety of the aircraft operation, are given. A concept for the development of actuators for the control surfaces of a passenger aircraft has been formulated, including the main directions of scientific and experimental work carried out by technical design companies, scientific organizations and manufacturers of hydraulic units both in Russia and abroad. The improvement of weight and size characteristics is possible due to the energy perfection of actuators and ensuring synchronization of their operation, the use of autonomous actuator circuits, and pumping stations of variable capacity. The issues of improving the dynamic characteristics of actuators involve the problems of increasing speed, accuracy, stability, and controllability. When considering promising design and layout schemes of actuators, the features of the use of electrohydrostatic actuators, integrated layout, electrohydraulic control and the advantage of an autonomous electrohydraulic actuator are shown. The section devoted to control systems characterizes fly-by-wire system, the use of Load Sensing (LS)-regulation of volumetric hydraulic machines, issues of performance management and integration with an intelligent computer control system. When considering the performance characteristics of perspective actuators, the possibilities of reducing heat losses, problems of increasing reliability and resource, and features of bench testing are highlighted. New directions for the development of actuators are considered, such as the use of fiber-optic control wiring instead of electric, as well as the use of plasma technologies for control surfaces.

Fuzzy pid control of electromechanical actuator system

In order to meet the needs of modern high-performance aircraft, the fuzzy PID control strategy was used to design the electromechanical actuator control system. This control strategy combines the advantages of fuzzy control and PID control, and has better adaptability to time-varying complex systems. The electromechanical actuator control system adopted the three-loop structure, and current loop, speed loop and position loop were built on the platform of MATLAB / Simulink. Considering that the discrete universe fuzzy PID control algorithm has good real-time performance with small online computation, the fuzzy PID controller in discrete universe was designed in the position loop and the system was simulated. The simulation results show that the dynamic and steady performance of discrete universe fuzzy PID control is better than that of traditional PID control, and it is more suitable for electromechanical actuator system.

Two degree of freedom robust data-driven fixed-order controller synthesis using convex optimization

Improvement of precise reference tracking performance of positioning systems is one of the essential objectives in feedback control design process. However, since the robustness of the feedback control system normally limits the fine positioning capacity, improvement in reference tracking performance with the desired robustness is difficult to be achieved. This paper proposes a new data-driven approach based on convex optimization to design two degree of freedom robust fixed-order H∞ controller for reference tracking. Linear time-invariant systems represented by non-parametric frequency domain data are considered. A semi-definite programming algorithm is employed to compute an optimal uncertainty model and the corresponding nominal model. Then, a novel sufficient robust performance condition is developed using Nyquist stability theorem and μ-synthesis methods for feedforward control systems. The proposed method allows formulating closed-loop model matching objective and robust performance conditions by convex functions. In addition, the presented two degree of freedom robust data-driven fixed-order controller design algorithm also can be directly applied to time-delay systems without any approximation and conservatism. The theoretical design approach is experimentally verified on position control of an electromechanical control actuation system of an air vehicle. To improve the positioning accuracy of the actuation system, the full-closed loop feedback structure is considered. Obtained experimental results verify the usefulness and efficiency of the proposed approach.

Torque Characterization of T-shaped Magnetorheological Brake Featuring Serpentine Magnetic Flux

Recently, T-shaped Magnetorheological Brake (MRB) usually utilize more than one wire coil electromagnetic to maximize magnetic flux reaching all Magnetorheological Fluid (MRF) gaps. This research was focused on the usage of a single wire coil on MRB with uniformly magnetic flux distribution. To achieve the goal, the serpentine magnetic flux profile was adopted to maximize all MRF gaps that only use a single coil. Firstly, the magnetic circuit which implementing serpentine magnetic flux was design in a two-dimensional model. It was then followed by magnetostatic simulation using Finite Element Method Magnetics (FEMM) to determine the amount of magnetic flux density. The data were then employed to calculate the braking torque. After having the final dimension and completing the workshop drawing, an MRB prototype was fabricated. Thus, the prototype was characterized using the braking test apparatus to figure out the torque profiles. Moreover, the experimental results were compared to the simulation results. This process justified the validity of the proposed mathematical model of the T-shaped MRB. It was investigated that the maximum braking torque from simulations and experimental works were 1.51 Nm and 1.91 Nm at 1 A, respectively. Overall the between differences of simulations and experimental works were about 10%. It is therefore, the mathematical model can be used for further application in the actuator control system.

Mode matching error signals using radio-frequency beam shape modulation.

Precise mode matching is needed to maximize performance in coupled cavity interferometers such as Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). In this paper, we present a new mode matching sensing scheme, to the best of our knowledge, that uses a single radio-frequency higher-order-mode sideband and single-element photodiodes. It is first-order insensitive to misalignment and can serve as an error signal in a closed loop control system for a set of mode matching actuators. We also discuss how it may be implemented in Advanced LIGO. The proposed mode matching error signal has been successfully demonstrated on a tabletop experiment, where the error signal increased the mode matching of a beam to a cavity to 99.9%.

A passive cooling design for an aircraft electromechanical actuator by using heat pipes

The more electric aircraft using the fly-by-wire technology is a developing trend for future aircrafts, in which the electromechanical actuator (EMA) is the key technique to realize the power-by-wire in the flight control actuation systems. The EMAs often suffer high heat generation during a short time, causing severe thermal problem, however, energy consumption and space for cooling systems are very limited on aircrafts. In this paper, a passive cooling design is proposed by transferring heat from the major sources of the EMA directly to fuel tanks by using heat pipes. The heat generation characteristics and the cooling performance of the EMA are experimentally investigated. The results show that the heat generation rates increase with the velocity and output force of the EMA, and efficient cooling for the EMA is performed by such a passive cooling device which decreases the temperature rise of the motor by 17.8% to 58.6% under different operation conditions. It is also found that the performance of this cooling device is majorly influenced by the coolant temperature and environmental temperature, while the impact of the coolant flow rate is not obvious. This work lays a foundation for the cooling design of the electromechanical actuators in an aircraft.

Construction and Analysis of Transplanting Robot Actuator Control System Based on Machine Vision

automated transplanting robots can liberate human labor and rapidly increase the speed of transplantation. This paper aims at the application of mechanical arms in transplantation by analyzing the force of the actuator during the transplantation process, and combines with the kinematics analysis of the actuator to create a control system for transplanting robot actuators based on machine vision, then simulates and verifies the transplanting robot actuators and control system, the result shows that the transplanting function is stable and the effect on plant protection is good.

Robust control for vibration control systems with dead-zone band and time delay under severe disturbance using adaptive fuzzy neural network

This study proposes a novel adaptive control method to deal with the dead-zone and time delay issues in actuators of vibration control systems. The controller is formulated based on a type-2 fuzzy neural network integrating with a new modification of Riccati-like equation. The developed new type Riccati-like equation is significant as it reduces energy consumption of control inputs to minimum. Two approaches are suggested to improve performance of the system using the basic elements of Riccati equation. In addition, a fuzzy neural network is applied to approximate the unmodeled dynamics and a sliding mode controller is developed to enhance the robustness of the system against uncertainties and disturbances. After proving the stability of the proposed controller via Lyapunov criterion, the effectiveness of the proposed approach is validated based on computer simulation for vibration control of a vehicle seat suspension. It is demonstrated that the unwanted vibrations due to external excitations are well controlled despite of the presence of dead-zone and time delay in actuators. Furthermore, when comparing with other two state-of-the-art robust controllers [23,33], the proposed controller provides better vibration suppression capacity and requires less energy consumption.

Comparative study between propulsion control system failures of an electrical vehicle piloted by FOC and by DTC using dual-induction-motors structure

Comparative study between propulsion control system failures of an electrical vehicle piloted by FOC and by DTC using dual-induction-motors structure