Lift Control Research Articles

Sprayed Liquid Flaps: A Numerical Assessment of a Multiphase Jet Concept

Sprayed liquid flap (SLF) is a novel powered-lift concept that utilizes an atomized liquid spray as a jet flap. Similar to a jet flap, SLFs modulate the flow and aerodynamics using a jet expelled on the pressure surface. However, SLFs differ through two mechanisms: 1) the liquid density is two orders of magnitude larger than the ambient air, and 2) the SLF medium has a porous-like character. The present effort explores SLFs using computational fluid dynamics at a state before experiments and therefore relies on benchmarks of underlying physics associated with a liquid-jet in crossflow. The studies evaluate flow rates, SLF positioning, and configurations spanning a range of flow conditions. The present investigation shows that SLFs can provide lift control combined with drag reduction with potential for application in aircraft. Additionally, the present study demonstrates that SLFs operate as a flow control device, not propulsion. Besides two-dimensional analysis, the SLF concept was investigated in three dimensions, which showed good consistency in potential applications despite three-dimensional effects on the SLF. Overall, this effort indicates the clear potential of a novel flow powered-lift control device useful for a range of aerodynamic applications.

A Novel Lift Controller for a Wind Turbine Blade Section Using an Active Flow Control Device Including Saturations: Experimental Results

A Novel Lift Controller for a Wind Turbine Blade Section Using an Active Flow Control Device Including Saturations: Experimental Results

Detection dataset of electric bicycles for lift control

Electric bicycle datasets for lift control have played a crucial role in the development of electric bicycle lift entry detection algorithms. However, existing datasets often encounter issues, including a small dataset size, a high false detection rate, and the absence of a publicly available benchmark dataset. This paper addresses these challenges by constructing a new electric bicycle detection dataset for lift control based on the research demands of the electric bicycle detection task for lift control. XHNet_EB, a car scene image dataset covering various types of electric bicycles, was constructed based on images taken by a camera from above. Segmented annotation was employed, framing the front and rear of the electric bicycle independently. This approach effectively addressed the problems of many irrelevant features and a high false detection rate caused by the use of whole-electric-bicycle annotations in mainstream datasets. AP_50, AP_75, the mAP, and the number of false detections in the images were used for quantitative analysis of the dataset. The experimental results indicated that the object detection accuracy of the XHNet_EB dataset was excellent. Quantitative analysis and evaluation of the number of false detections in images were conducted using four mainstream lightweight detection model algorithms. The results demonstrated that segmented annotation reduced the false detection rate more effectively than entire electric bicycle annotation. This study identified drawbacks in existing datasets. The dataset proposed in this paper overcomes the shortcomings of existing commercial data and solves problems such as the high false detection rate caused by the inclusion of many irrelevant features caused by the “whole-electric-bicycle annotation” method, which could help with the development of electric bicycle detection applications in lifts.

Fruit fly optimization algorithm with escape predation mechanism based direct lift control for automatic carrier landing

This paper designs a practical automatic carrier landing system (ACLS) that utilizes direct lift control (DLC) technology, and the controller parameters are optimized by using the enhanced fruit fly optimization algorithm with escape predation mechanism (EPFOA). The designed ACLS comprises the control channels of elevator, flap and throttle. The coordinated action of the elevator and flap can generate direct lift, enabling the aircraft to approach the desired glide path quickly and accurately. A decoupling module is designed to enhance the attitude stability of the aircraft during landing, thereby increase the success rate of landing. In order to achieve the better control effectiveness, the EPFOA is proposed to optimize the controller parameters of the DLC-based ACLS. Inspired by the predator-escape behavior between dingoes and sheep, EPFOA divides the whole fruit fly swarm into three categories: discovered escaping fruit fly (DEF), escaping fruit fly (EF) and predator fruit fly (PF). The PFs can ensure the population of convergence, while the DEFs and EFs can preserve the diversity of the population and avoid falling into local optima. Experiments are conducted in various cases, and the designed DLC-ACLS demonstrates superior ability in flight path adjustment and attitude control compared to the traditional F/A-18 ACLS in landing control. Additionally, the proposed EPFOA shows superior performance compared to other optimization algorithms.

Optimization of Elevator Usage by Image Processing for Optimal Energy Conservation

An efficient vertical transit system is a crucial feature of contemporary office buildings. Modern machine learning (ML) algorithms make it simple to optimise lift control strategies. This study proposes a revolutionary way to use Raspberry Pi camera module data for the best possible dispatching of traditional passenger lifts. It is assumed that an image processing system processes a real-time video to ascertain the quantity of people and objects utilising the lifts and waiting for a lift vehicle in the halls. These numbers are assumed to be connected to a specific uncertain probability. The efficiency of our unique lift control algorithm is derived from the need to serve a crowded floor completely, sending as many lifts as possible there and filling them to the maximum weight permitted, in addition to the probabilistic utilisation of the number of people and/or items waiting. The suggested technique introduces the idea of the effective number of persons and items to account for the uncertainty that may arise from the image processing system's imperfection. Reducing wait time, energy conservation and optimization are main the goals of this research. The proposed approach was implemented, and the simulation results showed that the passenger journey time was reduced. A three-story office building was the intended application for the prototype model. Key Words: Elevator, Raspberry Pi, Machine Learning, Optimization, Image Processing

Satellite design optimization for differential lift and drag applications

AbstractUtilizing differential atmospheric forces in the very low earth orbits (VLEO) regime for the control of the relative motion within a satellite formation is a promising option as any thrusting device has significant impact on system design due to the limited weight and size restrictions of small satellites. One possible approach to increase the available accelerations caused by the atmosphere is to reduce the mass of the respective satellites as well as to increase the available surface area. However, satellites of these characteristics suffer from rapid orbital decay and consequently have a reduced service lifetime. Therefore, achieving higher control forces is in contradiction to achieving a minimum orbital decay of the satellites, which currently represents one of the biggest challenges in the VLEO regime. In this article, the geometry of a given reference satellite, a 3UCubeSat, is optimized under the consideration of different surface material properties for differential lift and drag control applications while simultaneously ensuring a sustained VLEO operation. It is worth noting that both the consideration of sustainability as well as the optimization with regard to differential lift are new in literature. It was shown that the advantageous geometries strongly depend on the type of gas–surface interaction and thus, two different final designs, one for each extreme type, are presented. In both cases, improvements in all relevant parameters could be achieved solely via geometry adaptions.

Voice Operated Lift Control System With Safety

Voice Operated Lift Control System With Safety

Fault-tolerant control of automatic carrier landing using direct lift control based on nonsingular terminal sliding mode and active disturbance rejection control

This paper presents a fault-tolerant control scheme, combining nonsingular terminal sliding mode and active disturbance rejection control (NTSM-ADRC) to address actuator failure and external disturbances during the automatic carrier landing process of a carrier-based aircraft using direct lift control (DLC). First, the carrier-based aircraft model, the carrier air-wake model, and the actuator fault model were established. Second, the NTSM-ADRC controller is designed, The unmodeled dynamics of the system, the air-wake disturbance, and the fault term are treated as total disturbances and estimated accurately by extended state observer (ESO). To improve the response characteristics of the controller, the nonlinear error feedback control law is designed by combining the NTSMC. The Lyapunov function is constructed to prove the stability of the closed-loop system. The controller is applied to the aircraft DLC channel, attitude auxiliary channel, and approach power compensation system. The DLC improves the performance of fixed-wing aircraft by directly generating high lift through the flaps to change the aircraft trajectory. Finally, the method is tested by introducing various types of actuator failures. Simulation results demonstrate that the designed longitudinal fault-tolerant carrier landing system exhibits strong robustness and fault tolerance, thereby improving the accuracy of aircraft landing trajectory tracking.

An Innovative Lift Control Board Design and Prototype Production Using CANbus Communication System and STM32 Microcontroller

In this study, Önder Group Inc. Design Center, with an innovative approach, designed controllers for the first time, and prototypes were produced for a wide range of goods lifts according to different needs. With the innovative board design, goods lift users can choose parameters such as the number of floors, door types, and lock types from a user-friendly menu to suit their needs. Within the scope of the study, all functions that may be needed were identified, and the hardware structure of the system was determined. By simply changing the defined parameters, the desired goods lift controller can be made ready in a very short time. Time savings were achieved by simply expanding the hardware structure with the design of the CANbus communication system according to the number of floors and stops of the elevators. Thus, a wide range of lifts can be used by simply increasing the number of floor announcer boards and selecting the menu. Additionally, thanks to the designed Wi-Fi plug-in software, operators will be able to monitor the malfunction and operating status of the lift. With this plug-in, technical service teams can intervene immediately in case of malfunction.

Fault-Tolerant Control for Carrier-Based Aircraft Automatic Landing Subject to Multiple Disturbances and Actuator Faults

This paper introduces a fault-tolerant control scheme for the automatic carrier landing of carrier-based aircraft using direct lift control. The scheme combines radial basis function neural network and active disturbance rejection control (RBF-ADRC) to overcome the impact of actuator failures and external disturbances. First, the carrier-based aircraft model, the carrier air-wake model, and the actuator fault model were established. Secondly, ADRC is designed to estimate and compensate for actuator faults and disturbances in real time. RBFNN adjusts the ADRC controller parameters based on the system state. Then, the Lyapunov function is constructed to prove the stability of the closed-loop system. The controller is applied to the direct lift control channel, auxiliary attitude channel, and approach power compensation system. The direct lift control improves the performance of fixed-wing aircraft. Finally, comparative simulations were conducted under various actuator failures. The results demonstrate the remarkable fault tolerance of the RBF-ADRC scheme, enabling precise tracking of the desired glide path by the shipboard aircraft even in the presence of actuator failures.

Performance and Damage Study of Composite Rotor Blades under Impact.

A military helicopter is easily attacked by bullets in a battlefield environment. The composite blade is the main lifting surface and control surface of the helicopter. Its ballistic performance directly determines the vulnerability and survivability of the helicopter in the battlefield environment. To study the ballistic performance of the composite helicopter blade, the damage characteristics of the impacted composite rotor blade are obtained by experiments. A numerical simulation model is established by applying Abaqus software to predict the blade ballistic damage. The three-dimensional progressive damage failure model is used to analyze the ballistic damage under the experimental conditions. The effectiveness and accuracy of the numerical simulation model are verified through a comparison with the experimental results. The ballistic damage of composite blades under three experimental conditions was investigated. The results show that the ballistic damage type of composite blade mainly includes delamination, fiber breakage, and foam collapse. The damage to the composite material at the position of bullet incidence is mainly local shear fracture, while the damage to the composite material at the exit position is mainly fiber tensile fracture. The ballistic damage size of the composite blade is closely related to the ballistic position, incident angle, and structure characteristics along the ballistic path. The larger the incident angle, the smaller the ballistic damage size of the blade. The greater the structural stiffness of the structure near the exit, the greater the damage size of the exit. The numerical simulation model presented in this paper can provide a reference for research on the ballistic performance of composite helicopter blades.

Pembuatan Konsep Alat Preparasi Material Cangkang Kapsul Lunak Menggunakan Metode Pahl & Beitz

Softgel capsule is a capsule with soft shell texture and is used for fluid or semi-solid medicine substance. Research about softgel capsule in Politeknik Negeri Bandung uses a preparation device to mix the soft capsule shell ingredients. In its operation, this machine has several problems: ineffective method of loading and unloading of materials, unsuitable power for the mixing motor and heating element, and the control system still needs to be improved. Based on these problems, it is neccesary to reverse engineer the preparation device to get better design results so that the device can be operated more effectively. This study consists of three stages: planning, concept generation, and concept evaluation. At the planning stage, data is collected and compiled using the Quality Function Deployment (QFD) method to support the creation of requirement lists. In concept generation stage a design concept was created using the Pahl & Beitz method which was then evaluated using the Pugh weighting method until the final concept was obtained. There are three subfunctions: (1) lifting mechanism, (2) control system, and (3) unloading mechanism. The results of this study are a design concept with rack & pinion lifting mechanism, electrical control system, and sliding valve unloading mechanism.

Application of Reinforcement Learning in Decision Systems: Lift Control Case Study

This study explores the application of reinforcement learning (RL) algorithms to optimize lift control strategies. By developing a versatile lift simulator enriched with real-world traffic data from an intelligent building system, we systematically compare RL-based strategies against well-established heuristic solutions. The research evaluates their performance using predefined metrics to improve our understanding of RL’s effectiveness in solving complex decision problems, such as the lift control algorithm. The results of the experiments show that all trained agents developed strategies that outperform the heuristic algorithms in every metric. Furthermore, the study conducts a comprehensive exploration of three Experience Replay mechanisms, aiming to enhance the performance of the chosen RL algorithm, Deep Q-Learning.

Research on Aerodynamic Test Validation and the Vector Force Control Method for an E-STOL Fan Wing Unmanned Aerial Vehicle

The concept of the Fan Wing, a novel aircraft vector-force-integrated device that combines a power unit with a fixed wing to generate distributed lift and thrust by creating a low-pressure vortex on the wing’s surface, was studied. To investigate the unique propulsion mechanism of the Fan Wing, a Fan Wing test platform was developed, and experiments were conducted in a wind tunnel. At the same time, numerical simulations were established. In order to further improve the aerodynamic efficiency of the Fan Wing and decouple the control of lift and thrust, an improved scheme for the leading-edge structure of the Fan Wing was proposed, and a numerical analysis was conducted. A Fan Wing unmanned aerial vehicle (UAV) was designed and manufactured using the Fan Wing as the source of lift and thrust for the aircraft, and flight verification was conducted. The wind tunnel tests have proven that the main factors influencing the lift and thrust of the Fan Wing are rotation speed of cross flow fan, angle of attack, and incoming flow. The numerical analysis results of slotting on the leading edge show that the lift and thrust of the Fan Wing can be improved, but also the strength and position of the low-pressure vortices can be controlled. The results of flight tests show that the distributed lift and thrust of the Fan Wing can be directly applied to aircraft without the need for additional propulsion devices. In summary, the aerodynamic characteristics of the Fan Wing can be applied to electric short takeoff and landing (E-STOL) scenarios in urban air traffic.

Numerical investigation of virtual control surfaces for lift control on NACA0015 airfoil

The plasma actuators as virtual control surfaces are assessed numerically as a means to control the lift of NACA0015 airfoil at the full angle of attack (without stall). The virtual control surface for increasing lift is realized by the pressure side (PS) plasma actuators that induce an upstream jet and the suction side (SS) plasma actuators that induce a downstream jet (SSD plasma actuator), while the one for reducing lift is realized by the SS plasma actuators that induce an upstream jet (SSU plasma actuator). Numerical simulation is achieved by solving the two-dimensional Reynolds averaged Navier–Stokes using the finite volume method. The plasma actuator adopts the empirical model proposed by the author before. The simulation of the air flow was performed for the freestream velocity of 20 m/s (Re=1.03 × 106) and the induced jet momentum coefficient between 0.0846% and 0.9027%. The calculation results show that the optimal number of DBD actuators for increasing the lift is related to the angle of attack. The SS flow separation of the high angle of attack greatly reduces the control effect of the PS actuator, which can be eliminated by arranging the actuators in front of the separation point. Finally, a virtual control surfaces configuration containing three groups of seven plasma actuators is obtained.

Nonsingular Fast Terminal Sliding Mode Neural Network Decentralized Control of a Quadrotor Unmanned Aerial Vehicle

A nonsingular terminal sliding mode decentralized controller that can ensure the tracking errors of the trajectories and attitude rapid convergence in finite time is proposed for an insufficient driven and strongly coupled nonlinear four-rotor unmanned aerial vehicle (UAV). The total lift of the UAV system is decomposed into three virtual drive separation forces corresponding to the three positions. The insufficient drive UAV system is transformed into a virtual full-drive model for research. The three position states and the three attitude states of UAV are placed correspondingly to the six subsystems by variable substitution. The model uncertainty and unknown disturbance term for each subsystem serves as total coupling terms among the subsystems. The upper bounds of the total coupling terms are considered as unknown ordinary higher order polynomials varying with the six states of the system under the action of time change. With the help of Cauchy inequality, the estimates of the upper bounds are obtained from the approximation performance of the RBF neural network. Finally, the decentralized controller is designed for each attitude subsystem and the virtual decentralized controller for each position subsystem. It is also mapped to the tracking total lift controller by using the virtual decentralized position controller. The controller design process uses the nonsingular terminal sliding mode control technology to ensure that the quadrotor attitude and position variables can quickly converge to the desired value in a short time. Simulation experiments verify that the proposed control method is effective and feasible.

Nondestructive Forensic Investigation of a Scissor Lift Fatality

After a worker was found fatally pinned between the top rail of a scissor lift and an overhead beam, rescue attempts were frustrated by unresponsive lift controls. In the investigation of this fatal accident, certain lift controls did not function or functioned intermittently. The intermittent nature of the malfunction indicated that the evidence was sensitive — likely to be disturbed if the device was disassembled using typical destructive techniques. Therefore, nondestructive techniques were required. This study discusses how X-ray imaging, computed tomography (CT), electrical testing, and engineering analysis of the lift and control system were used to investigate the causes and contributing factors of this fatal accident without disturbing sensitive evidence.

Research on Direct Lift Carrier-Based Unmanned Aerial Vehicle Landing Control Based on Performance Index Intelligent Optimization/Dynamic Optimal Allocation

High-precision control problems for carrier-based UAVs are challenging due to the requirements for safety, high-performance operation and uncertain ocean environments. To address such problems, this paper proposes a direct lift landing control method that can ensure the safe operation of UAVs using intelligent optimization of control performance indicators and dynamic optimal allocation methods. The direct lift control (DLC) scheme is adopted to improve the operability of the control by introducing flap channels to achieve the fast correction of vertical disturbances. To improve the landing control performance, an intelligent optimization method for DLC gain is proposed, and a neural network relationship between parameter uncertainty and optimal DLC gain is established. In addition, a recursive least-squares identification method is used to estimate the uncertain parameters in real time, so that the established neural network can be used to generate the optimal DLC commands online, and the generated control commands can be assigned to multiple actuators of the carrier-based UAV through a dynamic optimal assignment algorithm. Finally, the superiority of the method is verified using simulation comparison.

Constraint‐based multi‐agent reinforcement learning for collaborative tasks

AbstractIn order to be successfully executed, collaborative tasks performed by two agents often require a cooperative strategy to be learned. In this work, we propose a constraint‐based multi‐agent reinforcement learning approach called constrained multi‐agent soft actor critic (C‐MSAC) to train control policies for simulated agents performing collaborative multi‐phase tasks. Given a task with phases, the first phases are treated as constraints for the final task phase objective, which is addressed with a centralized training and decentralized execution approach. We highlight our framework on a tray balancing task including two phases: tray lifting and cooperative tray control for target following. We evaluate our proposed approach and compare it against its unconstrained variant (MSAC). The performed comparisons show that C‐MSAC leads to higher success rates, more robust control policies, and better generalization performance.

Design and implementation of spanwise lift and gust control via arrays of bio-inspired individually actuated pneumatic flaplets

PurposeCovert feathers on avian wings can show dynamic pop-up behaviour in rapid succession as a reaction to turbulent gusts. The purpose of this paper is to understand the possible flow control mechanism induced during such dynamic motion cycles. A model aerofoil is designed with suction side spanwise control of rows of bio-inspired flaplets.Design/methodology/approachA NACA 0012 aerofoil is equipped with a spanwise row of eight flaplets at 80% chord, connected to pneumatic actuators and can be deployed to max 15° in a prescribed open–hold–close manner. The model is placed in a water tunnel and flow measurements are done in the wake of the flaps during a cycle using particle image velocimetry.FindingsDuring opening, boundary layer flow is sucked into the void space between the wing surface and the flaplet, which induces backflow underneath the flaplet and traps the fluid inside. This fluid is expelled downstream during closure, which generates a forward directed jet as seen by the formation of a vortex-ring like structure with higher axial momentum. The entrainment of the jet leads to the re-energising of the boundary layer flow further upstream.Originality/valueThis paper presents a furtherment of understanding of the action of pop-up feathers for separation control. The actuation of the bio-inspired flaplets shows a flow vectorising effect which can be used for active separation and gust control. In the case of incipient separation, flaplet action can act to re-attach the flow because of the jet entrainment effect.