22 results about "Helicopter dynamics" patented technology

The present application belongs to the technical field of helicopter dynamics test, and relates to a method and system for measuring the distance between blades of upper and lower rotors based on measured bending moment. The measured bending moment data in flight is used, and the existing blade measurement system is used. Without additional measurement equipment, the relationship between bending moment and deformation is used to establish the calibration relationship between the test bending moment and the deformation of different profiles of the blade, so as to obtain the distance between the blades of the upper and lower rotors in the real-time flight state. The method can relatively real-time monitor the distance between the blades of the upper and lower rotors in the full flight spectrum state without additional measurement equipment, and ensure flight safety. The method has the advantages of simplifying the measurement method of the blade tip distance, shorter feedback time compared with the light ray sensor and radar wave measurement, and better real-time effect.

The present application belongs to the field of helicopter dynamics, and relates to a torsional vibration analysis method for a bearingless rotor unmanned helicopter transmission chain torsional vibration system. The method comprises: analyzing the structure type and structure connection mode of the bearingless rotor, establishing a bearingless rotor unmanned helicopter blade finite element analysis model, thereby defining the equivalent flapping hinge position; based on the finite element analysis model and the equivalent flapping hinge position, obtaining the flapping modal frequency and mode shape of the isolated blade; analyzing the scheme of the bearingless rotor unmanned helicopter power / transmission system, establishing a power / transmission system finite element analysis model, thereby obtaining the power / transmission system torsional vibration frequency and mode shape; regarding the rotor system composed of several bearingless rotor unmanned helicopter blades as a subsystem, regarding the power / transmission system as a subsystem, coupling the finite element analysis models of the two subsystems at the main hub, obtaining the inherent characteristics of the coupled state rotor / power / transmission system, i.e. the torsional vibration calculation result of the transmission chain torsional vibration system.

The application discloses a helicopter low-altitude flight path planning method based on motion state search and enhanced safety pipeline, which comprises the following steps: firstly, based on a grid map, segmented flight path planning is carried out to generate a helicopter motion state space considering dynamic constraints and maneuvering characteristics; then, after the state space is expanded and a cost function is established, an optimal path search is carried out in the expanded state space by using an improved hybrid A* algorithm; then, in a local map which is updated in real time according to dynamic threats, an enhanced safety pipeline is generated by expanding, pruning and interpolating based on the initial flight path according to the safety constraints of the flight path; finally, the B-spline curve is used to fit the flight path in the enhanced safety pipeline, and the curve parameters are optimized by using the minimum cost criterion, so that the helicopter low-altitude flight path planning optimization is realized. According to the application, the state space considering the dynamic constraints and maneuvering characteristics of the helicopter is used to generate the enhanced safety pipeline in real time and to serve as the optimization space of the fitting parameters of the rear-end flight path, so that the adaptability of the planned flight path to the execution process of the helicopter is improved, and the flight safety of the helicopter under the dynamic threats at low altitude is effectively improved.

The invention belongs to the technical field of helicopter dynamic flight simulation, and particularly discloses a rolling frame suitable for a dynamic flight simulator, which comprises a frame body, the frame body comprises an annular upper half frame and an annular lower half frame, and the upper half frame and the lower half frame are mutually buckled and connected to form a frame body structure. The two opposite sides of the upper half frame and the lower half frame are connected with interfaces which are coaxially arranged, and the upper half frame and the lower half frame are of frame structures made of carbon fiber composite materials. The quality of the rolling frame can be effectively improved.

The invention relates to the technical field of helicopter control, in particular to a method for optimizing a fuzzy PID (Proportion Integration Differentiation) controller to control a helicopter attitude. In order to solve the problem that a traditional parameter optimization method of a fuzzy PID (Proportion Integration Differentiation) controller mainly depends on expert experience, so that the control precision of the helicopter attitude is low, the invention provides a novel method for optimizing a fuzzy PID controller to control the helicopter attitude, which comprises the following steps of: 1) establishing a helicopter kinetic model and a kinematics model; 2) performing parameter optimization on a quantization factor and a scale factor in the fuzzy PID controller by adopting a plant growth simulation algorithm and genetic algorithm hybrid optimization method to obtain a global optimal parameter; and 3) assigning the global optimal parameter to a quantization factor and a scaling factor in the fuzzy PID controller to form a complete control closed loop of the fuzzy PID controller to complete helicopter attitude control. The control method provided by the invention significantly improves the precision of helicopter attitude control.

The application belongs to the technical field of helicopter dynamics design, and discloses a kind of fast evaluation method of helicopter rotor body coupling stability frequency design, based on the change relation of rotor system characteristic frequency and body modal frequency with rotor speed, resonance center speed and speed stability margin are obtained, to carry out the fast evaluation of rotor body coupling stability, and according to the result of fast evaluation, whether the speed stability margin meets the design requirement is determined, to carry out the optimization design of rotor system characteristic frequency and body modal frequency, which can ensure that the rotor body coupling stability meets the design requirement in the early stage of design. The application avoids the problem of rotor body coupling stability, can carry out frequency design more accurately in each stage of type design, and has high universality and engineering application value.

The present application belongs to the technical field of helicopter fatigue test, and particularly relates to a helicopter moving ring fatigue test device and a test method. The device is composed as follows: a lower bottom surface of a stationary ring dummy mounting support is mounted on a fixed platform, and a stationary ring dummy is mounted above the stationary ring dummy mounting support; an outer cylindrical surface of the stationary ring dummy is mounted through interference fit with an inner cylindrical surface of a helicopter moving ring large bearing; a cylinder base is mounted on the fixed platform and is uniformly distributed around the stationary ring dummy mounting support, a fixed end of the cylinder is connected with the cylinder base, a loading end of the cylinder is connected with a variable torque rod loading connector, the other end of the variable torque rod loading connector is fixed to a helicopter moving ring support arm; a torsion arm loading yoke assembly is connected with a helicopter moving ring 2# torsion arm, a torsion prevention yoke assembly is connected with a helicopter moving ring 1# torsion arm at one end and connected with a torsion prevention rod assembly at the other end; the torsion arm loading yoke assembly and the torsion prevention rod assembly are fixed with a ground rail through a torsion arm loading support.

The present invention relates to the field of helicopter control technology, and specifically to a method for optimizing a fuzzy PID controller to control helicopter attitude. To address the problem that traditional fuzzy PID controller parameter optimization methods primarily rely on expert experience, resulting in low control accuracy for helicopter attitude, the present invention provides a new method for optimizing a fuzzy PID controller to control helicopter attitude, comprising the following steps: 1) establishing a helicopter dynamics model and a kinematic model; 2) optimizing the quantization factor and proportional factor in the fuzzy PID controller using a hybrid optimization method of a simulated plant growth algorithm and a genetic algorithm to obtain globally optimal parameters; and 3) assigning the globally optimal parameters to the quantization factor and proportional factor in the fuzzy PID controller to form a complete control closed loop for the fuzzy PID controller, thereby completing helicopter attitude control. The control method of the present invention significantly improves the accuracy of helicopter attitude control.

The invention discloses a two-degree-of-freedom helicopter preset performance tracking control method based on reinforcement learning. The method comprises the following steps: constructing a two-degree-of-freedom helicopter dynamic model; a preset performance function is introduced, a constrained tracking error is converted into an unconstrained form through error conversion, and therefore it is guaranteed that the system reaches a steady state within preset time; designing a preset time nonlinear disturbance observer; based on a backstepping control architecture, combining with a predefined time filter, and decomposing the system into two stages of subsystems through coordinate transformation; an optimal performance index function is constructed for each stage of subsystem, an optimal control strategy is approached online by using a reinforcement learning algorithm, and an optimal virtual controller and a self-adaptive optimal actual control law are designed. According to the method, all signals in a two-degree-of-freedom helicopter closed-loop system can be converged and bounded within predefined time, transient and steady state response indexes of the system are improved, and it is ensured that the helicopter can still rapidly and accurately track a reference trajectory under complex working conditions and quantized limited conditions.

The invention relates to the field of full-size helicopter target hovering methods, and discloses a reinforcement learning-based full-size helicopter target hovering method, which comprises the following steps of: firstly, establishing a dynamic model of a full-size helicopter UH-60; then, the award mechanism of the hovering task is improved, and the exploration space of the helicopter is greatly expanded; however, the convergence speed of the reinforcement learning algorithm is obviously reduced, and in order to accelerate convergence, a curiosity exploration mechanism based on random network distribution is introduced to improve the training efficiency; besides, in consideration of high nonlinearity and complexity of helicopter dynamics, in order to better capture long-distance correlation in time and space in state information, a self-attention mechanism is introduced into an Actor network of reinforcement learning, finally, the model is trained, and a training result is displayed.

The present application belongs to the field of helicopter vibration control, and relates to a power absorber engineering design method for local vibration control of a helicopter. The method comprises the following steps: determining an optimal installation position of the power absorber by carrying out power absorber and helicopter dynamics coupling analysis; determining an optimal effective mass of the power absorber in combination with overall design requirements of the power absorber; and carrying out power absorber structure design based on the effective mass of the power absorber.

The present application belongs to the field of helicopter vibration data processing, and relates to a method and device for processing and classifying helicopter flight vibration data. The method comprises: collecting flight vibration data of each measuring point position of a helicopter; classifying the helicopter flight vibration data according to a helicopter flight profile to determine the flight state in which the vibration response is located; classifying the flight vibration data according to the vibration environment requirements of the helicopter to determine the influence of different vibration sources of the helicopter on the measuring point position; for the same measuring point position, processing the flight vibration data of the measuring point position to obtain the vibration response of the measuring point position under the concerned vibration source in different flight states according to the flight profile; analyzing the obtained vibration response, analyzing the vibration response of each part of the helicopter in combination with the full-aircraft transfer function test and the component dynamic characteristic test, judging the accuracy and rationality of the vibration response of the machine body, and analyzing the helicopter full-aircraft flight vibration level in combination with the helicopter dynamics theory.

The invention discloses a multi-platform unmanned helicopter dynamic scheduling method and system based on an improved tabu search algorithm, and relates to the field of unmanned helicopter scheduling, and the method comprises the steps: constructing a dynamic scheduling model of an unmanned helicopter; the dynamic scheduling model is used for simulating the whole process of combat-guarantee of the unmanned helicopter; constraints of the dynamic scheduling model comprise task stage logic constraints and resource constraints; solving the dynamic scheduling model based on an improved tabu search algorithm to obtain an initial scheduling scheme; carrying out local rescheduling on the initial scheduling scheme based on a multi-modal disturbance perception adaptive rescheduling strategy to obtain a rescheduling scheme; and updating the global task plan of the multi-platform unmanned helicopter based on the rescheduling scheme. According to the invention, integrated modeling of the combat mission and the guarantee operation can be realized, the dynamic environment adaptability is improved, and the accurate scheduling of the unmanned helicopter is improved.

The invention belongs to the technical field of helicopter dynamics design, and discloses a method for analyzing the influence of a helicopter fairing on vibration, which comprises the following steps of: 1, acquiring test flight actual measurement data, and processing and analyzing vibration data characteristics of typical positions at typical moments; 2, determining the vibration influence mechanism of the fairing; 3, classifying vibration mechanisms, and analyzing main influence factors; 4, classifying ways for solving the vibration problem; 5, fairing optimization is conducted according to different ways; step 6, carrying out test flight verification and result comparison; step 7, if verification shows that the vibration problem disappears, ending; and if the verification shows that the vibration problem still exists, repeating the steps 5-6 until the vibration problem disappears. According to the method, the problem that helicopter vibration is caused by fairing design is solved, a universal method for solving the problem can be obtained, and the method has high engineering value in vibration problem investigation, vibration control plans and other work.

The present invention belongs to the technical field of ship and ocean engineering, and discloses a method and system for judging the stable period state of helicopter deck takeoff and landing. The method includes: constructing a multi-layer long short-term neural network prediction model Multi-LSTM-Aero based on dynamic constraints, reading and preprocessing ship motion data and environmental wind field data; predicting the three-degree-of-freedom motion envelope of the ship; predicting environmental wind field data; calculating the helicopter dynamic model with the prediction results of the ship's three-degree-of-freedom motion envelope and the prediction results of environmental wind field data; based on the obtained prediction results of helicopter control quantities and helicopter attitude quantities, judging and calculating the stable period of deck takeoff and landing through the set corresponding helicopter control limits and attitude limits. The present invention can effectively improve the ability of operation personnel and command personnel to grasp the takeoff and landing state, and provide technical support for improving the efficiency and safety of takeoff and landing operations.

The application discloses a kind of helicopter safety flight boundary determination method, device, equipment, medium and product, it is related to helicopter technical field, the method includes obtaining the mass center speed vector of helicopter, attitude angle vector and angular velocity vector;According to mass center speed vector, attitude angle vector and angular velocity vector utilize helicopter dynamics characteristics to construct helicopter nonlinear model and constraint range;According to the helicopter nonlinear model and the constraint range utilize alpha shape method and heuristic algorithm to determine helicopter attitude angle rate safety boundary;According to the helicopter attitude angle rate safety boundary utilizes DFoG method to determine helicopter attitude angle safety boundary;According to helicopter nonlinear model, the helicopter attitude angle rate safety boundary, the helicopter attitude angle safety boundary and the constraint range determine helicopter speed safety boundary, the application can improve the accuracy of helicopter safety flight boundary.

The invention discloses a helicopter dynamic balance detection and verification platform and method, the helicopter dynamic balance detection and verification platform comprises a platform body, a driving mechanism and a detection mechanism, the platform body is provided with an adapter shaft, the adapter shaft passes through the platform body and is pivotally connected with the platform body, and the adapter shaft is connected with the detection mechanism. The rotating connection shaft is sequentially sleeved with the blade installation disc and the balance weight disc in the preset direction, a plurality of blade installation holes are formed in the blade installation disc, a plurality of balance weight holes are formed in the balance weight disc, and the driving mechanism is located on the platform body and is in transmission connection with the rotating connection shaft. The detection mechanism comprises an acceleration sensor, a photoelectric sensor and a dynamic balance detection device, and the acceleration sensor and the photoelectric sensor are electrically connected with the dynamic balance detection device. The helicopter dynamic balance detection verification platform and method have the advantages that the simulation effect is close to the actual working condition, and the verification efficiency is high.

The application discloses a kind of based on composite cost function's helicopter dynamic route planning method and system, it is related to route planning technical field, including: obtaining the multi-source data of target area and fusion generation dynamic three-dimensional terrain model;Based on target area setting take-off point and multiple potential landing points;Based on landing point adaptability comprehensive evaluation cost function evaluation all landing points, obtain optimal landing point;Based on take-off point and optimal landing point, in combination with flight complexity cost function, obtain current optimal exploration area;Based on current optimal exploration area in combination with depth coupling cost function, screening obtains candidate flight node;Based on candidate flight node screening obtains optimal flight node of current exploration area;Based on take-off point, optimal flight node and optimal landing point obtain current optimal route;Based on current optimal route flight, and dynamically update subsequent route when abnormal. Improve the safety, efficiency and reliability of post-disaster helicopter rescue.

The application provides a kind of helicopter landing gear dynamics modeling method based on Adams, three-dimensional model of helicopter body and landing gear is respectively established, and the three-dimensional model is imported into Adams;Hydro-pneumatic buffer is equivalent to a gas spring, an oil damper and a friction damper parallel mechanism, the mathematical model of hydro-pneumatic buffer is established;Combined with Adams in Faila tire mechanics model and tire model interface, the modeling of tire vertical force, longitudinal force, lateral force and turning moment is carried out;The current time tire motion state information is obtained from the tire model interface of Adams, the tire force and torque are calculated and output, and the tire model interface is returned to Adams, the motion state of the next simulation time is calculated, and iterative analysis is carried out.The technical scheme of the application can solve the problem of long solving time and low efficiency of traditional dynamics modeling method of helicopter landing gear, realize the rapid solution of helicopter dynamics characteristics and adjustable dynamics model parameters.

The invention belongs to the technical field of helicopter dynamics, and particularly relates to a coaxial helicopter body undercarriage coupling dynamics modeling method. The method comprises the following steps: 1, establishing a coaxial helicopter body dynamic model based on a helicopter prototype structure mathematical model and a finite element modeling method; 2, carrying out an undercarriage static pressure test and a rigidity damping characteristic test to obtain a static pressure curve and a rigidity damping characteristic test result of a buffer strut and an airplane wheel; and 3, establishing an airframe undercarriage coupling dynamic model by utilizing intersection data of the undercarriage and the airframe and a test result obtained in the step 2, and carrying out finite element simulation calculation.

The invention belongs to the technical field of helicopter dynamics design, and discloses a rapid evaluation method for helicopter rotor body coupling stability frequency design, and the method comprises the steps: obtaining a resonance center rotating speed and a rotating speed stability margin based on the change relation of a rotor system characteristic frequency and a body modal frequency along with the rotor rotating speed; according to the method, the rotor body coupling stability is rapidly evaluated, whether the rotating speed stability margin meets the design requirement or not is determined according to the rapid evaluation result, optimization design of the rotor system characteristic frequency and the body modal frequency is carried out, and it can be ensured that the rotor body coupling stability meets the design requirement at the initial stage of design. According to the method, the problem of coupling stability of the rotorcraft body is avoided, frequency design can be more accurately carried out in each stage of model design, and the method has very high universality and engineering application value.