CN-122018564-A - Real-time track planning method and system for steady-state autorotation segment after helicopter power failure

CN122018564ACN 122018564 ACN122018564 ACN 122018564ACN-122018564-A

Abstract

The invention discloses a real-time track planning method and a system for a steady-state autorotation segment after power failure of a helicopter, which relate to the technical field of track planning of helicopters and comprise the steps of initializing a system and reading current helicopter state information as an initial point; the method comprises the steps of calculating an reachable area of a landing point, selecting a target landing point and a course angle as termination points, setting path parameters, planning a plane track, dividing the path into a turning section S1, a straight line section L2 and a turning section S3, solving a vertical track, obtaining a whole track through linear interpolation and integration of a key node descent rate, judging errors, optimizing the path parameters if the errors do not accord with the critical node descent rate, comparing costs, selecting an optimal three-dimensional track, and updating in real time. The method and the device greatly improve the calculation speed while ensuring the accuracy and the reliability of the generated track so as to realize the real-time generation and the update of the track under different working conditions. By setting the cost function and the judgment criterion, the method performs preferential selection on the basis of ensuring that a feasible track exists, and ensures the quality of the landing track.

Inventors

Cao Chenkai
ZHANG BOXIANG
ZHANG SHIZHEN
XU YOUSONG
ZHAO QIJUN
CHEN ZHE
Wei Kangrui
ZHOU XU
ZHAO YIHANG
JIANG BEI

Assignees

南京航空航天大学

Dates

Publication Date: 20260512
Application Date: 20251217

Claims (10)

1. A real-time track planning method for steady-state autorotation segments after helicopter power failure is characterized by comprising the following steps: Initializing a system and reading state information of a current helicopter to serve as initial point state information; Calculating a landing point reachable area according to the initial point state information, namely a pre-landing point maximum distribution area capable of realizing safe landing operation through a self-rotation downslide flight mode; the driver or an automatic system selects a safe and barrier-free target landing point and an expected landing course angle in a displayed reachable area, and sets the ideal entering speed and the ideal entering height of a near-ground landing stage as termination point state information; Setting and assigning path parameters, wherein the path parameters are expressed as duration time, acceleration and yaw rate of the turning section; According to the state information of the starting point and the ending point, planning a plane track by combining the path parameters, dividing the path into a turning section S1, a straight line section L2 and a turning section S3, and adopting a parameter optimization algorithm to ensure the first-order continuity requirement; the vertical track corresponding to each plane track is calculated, the descent rate is obtained through the forward flight speed and time nodes of the four key nodes, and linear interpolation is carried out on the descent rate track to obtain a whole-course descent rate change track and a descent height track; Judging whether each vertical track meets the requirements, if not, returning to the step to correct the path parameters and re-plan the plane track and the vertical track until the error requirements are met; Comparing the optimized cost of all the feasible paths, selecting the path with the minimum cost as the final planned optimal three-dimensional sliding track, and outputting the optimal track information to a flight control system or displaying the optimal track information on a cockpit display; In the autorotation and downslide process, the system periodically returns to the steps according to the deviation between the actual state of the helicopter and the planned track, recalculates the initial point state information and the landing point reachable area, and updates the target landing point and the path parameters so as to adapt to wind field change, topography uncertainty and flight state deviation.
2. The method for planning the real-time track of the steady-state rotation segment after the power failure of the helicopter according to claim 1, wherein the initial state information of the helicopter comprises the current altitude, the forward flying speed and acceleration of the helicopter, a course angle, the rotating speed of the rotor and a descent rate, and the course angle is defined as an included angle between the course of the helicopter and the north direction in a north-east-earth coordinate system, and the anticlockwise direction is positive.
3. The method for planning the real-time track of the steady-state autorotation segment after the power failure of the helicopter according to claim 1, wherein the calculation of the landing site reachable region comprises the steps of calculating the farthest sliding boundary capable of realizing safe landing through autorotation downslide by utilizing the minimum descending rate capable of realizing the optimal sliding performance in quasi-steady-state trimming data based on an optimal energy management principle, calculating the nearest sliding boundary capable of realizing safe landing by utilizing the maximum descending rate in the quasi-steady-state trimming data on the premise of limiting the course angle change of the helicopter to not more than 180 degrees under the premise of considering the control delay and various energy loss factors, wherein the region surrounded by the farthest sliding boundary and the nearest sliding boundary is the landing reachable region, and the region comprehensively considers the terrain, wind field and the mechanical performance constraint of the helicopter.
4. The method for planning the real-time track of the steady-state rotation segment after the power failure of the helicopter according to claim 1, wherein the planning of the planar track comprises the steps of selecting a target landing point in a landing reachable area, acquiring coordinates of a starting point and a finishing point and a course angle constraint, considering the mobility constraint of the helicopter, particularly a minimum turning radius constraint determined by a maximum rolling angle; The path parameter set comprises duration time, acceleration and yaw rate of the turning section, the acceleration and yaw rate of the turning section S1 and the turning section S3 are given by the parameter set, the forward flying speed and the course angle are expressed as first-order linear functions of time, and boundary point coordinates of the turning section are calculated, the straight line section L2 is a common tangent line of the turning section S1 and the turning section S3, and the calculation is carried out by adopting a parameter optimization algorithm to ensure that the track meets the first-order continuity requirement.
5. The method for planning the real-time track of the steady-state rotation segment after the power failure of the helicopter according to claim 1 is characterized in that the calculation of the vertical track corresponding to each plane track comprises the steps of taking in the mapping relation between the quasi-steady-state descent rate and the flight state according to the forward flight speed and the time node of four key nodes of the plane track, obtaining descent rates corresponding to the four key nodes, carrying out linear interpolation on the descent rates of the four key nodes to obtain a whole-course descent rate change track, and integrating the numerical values of the descent rate track along a time axis to obtain the descent height track.
6. The method for planning the real-time track of the steady-state autorotation segment after the power failure of the helicopter according to claim 1, wherein the judging whether each vertical track meets the requirements comprises defining an error of the vertical track as a difference value between a planned height and an actual integral height, returning to the path parameter setting step if the error exceeds a preset threshold value, and correcting the path parameter or correcting the path parameter and recalculating cost if the error exceeds the preset threshold value; The correction adopts a gradient descent algorithm to carry out iterative optimization, and comprises the steps of inputting initial parameters, learning rate, convergence threshold and maximum iteration times, calculating the gradient of a cost function and updating parameters until convergence conditions are met or the maximum iteration times are reached; constraints of the path parameters include a turn section duration range, an acceleration range, and a yaw rate range.
7. A real-time trajectory planning method for steady-state autorotation segments after helicopter power failure as claimed in claim 1 wherein said outputted optimal trajectory information comprises a three-dimensional waypoint sequence, each stage control reference, and predicted arrival target point time and remaining altitude.
8. A real-time trajectory planning system for a steady-state autorotation segment after a helicopter power failure, based on the real-time trajectory planning method for a steady-state autorotation segment after a helicopter power failure according to any one of claims 1 to 7, comprising: The sensing system is internally provided with a power failure monitoring module, a flight state acquisition module and an environment terrain sensing module, and is used for acquiring the power failure state, steady-state rotation section key parameters, environment obstacles and terrain data of the helicopter in real time and providing basic data for subsequent planning; the data processing system is internally provided with a data cleaning module and a multi-source data fusion module, which are used for solving the problems of noise, missing and non-uniform format of the sensing layer data, generating standardized and highly reliable input data and avoiding track planning deviation caused by error data; The core planning system is internally provided with an reachable region calculation module, a candidate landing point generation module, a planar track planning module and a three-dimensional track optimization module, and based on the preprocessed data set, a 'safe, feasible and optimal' landing track is generated in real time by combining a kinematic model of a steady-state autorotation segment of the helicopter; and the man-machine interaction system is internally provided with a system state and track display module, and feeds back the system state and track information to the pilot in real time, and simultaneously reserves manual intervention permission of the pilot.
9. A computer device comprises a memory and a processor, wherein the memory stores a computer program, and the computer program is characterized in that the processor realizes the steps of the real-time track planning method for the steady-state autorotation segment after the power failure of a helicopter according to any one of claims 1-7 when executing the computer program.
10. A computer readable storage medium, on which a computer program is stored, is characterized in that the computer program, when executed by a processor, implements the steps of the method for real-time trajectory planning for steady-state autorotation segments after a power failure of a helicopter according to any one of claims 1 to 7.

Description

Real-time track planning method and system for steady-state autorotation segment after helicopter power failure Technical Field The invention relates to the technical field of helicopter track planning, in particular to a real-time track planning method and a real-time track planning system for a steady-state autorotation segment after power failure of a helicopter. Background The engine failure occupies the main reason of aviation accident for a long time, and compared with a fixed wing aircraft, the helicopter has more complicated and severe service conditions and working environments, thereby causing higher aviation accident. The autorotation and downslide are special flight states for maintaining the rotating speed by utilizing airflow to drive the rotor wing, are one of the main characteristics of the rotor wing aircraft, and are unique and unique safe landing methods after the failure of the helicopter engine. The typical spin-down process can be divided into several phases from time history, leading in, steady state spin, deceleration leveling, landing, and touchdown coasting. The steady-state autorotation is used as a stage with the longest span in the time and space domain, has a larger planning space, and a driver usually utilizes the stage to select a proper landing place, properly and stably change the forward flying speed and the descent rate, and operate the helicopter to drive to a target position and prepare for the subsequent near-ground landing stage. In the process of self-rotation and sliding down, a large amount of uncertain factors are accompanied, in the actual process, a driver often operates the helicopter through personal experience so as to realize forced landing to a designated place, and the method has extremely high operation requirement on the driver and has low success rate. At this time, if the organic vehicle-mounted auxiliary driving system can take over the driver to complete the energy management and track planning process according to the current flight state, the operation pressure of the driver can be greatly reduced, and the landing success rate is improved. At present, some universities and research institutions at home and abroad have developed the track planning research of the helicopter in the rotation downslide stage, and mainly focus on calculating the state quantity and control quantity track in the downslide process by an optimal control method. For example, patent CN119200661a discloses a safe track planning method for helicopter autorotation landing, which comprises the steps of firstly determining state quantity and control quantity according to a nonlinear autorotation dynamics model, then setting a key objective function and flight constraint conditions, constructing an autorotation landing optimization model, and finally solving the optimization model by using a gaussian pseudo-spectrum method from the optimal control point of view to obtain an autorotation landing track. The method can generate an accurate track, but because of the dependence on the optimal control solution with high calculation complexity, the method has higher calculation cost and longer calculation time, cannot be well suitable for a real-time human-computer interaction scene under the special condition of engine failure, has higher requirement on hardware, and has limitation in practical airborne application. Therefore, a real-time track planning method is needed to ensure the accuracy and reliability of the track generated by the steady-state rotation segment of the helicopter, and greatly improve the calculation speed, so as to realize real-time generation and updating of the track under different working conditions. Disclosure of Invention The invention is provided in view of the problems of low solving efficiency, high hardware requirement and the like of the existing optimal control method when the engine fails. Therefore, the problem to be solved by the invention is how to provide a real-time track planning method and a system for steady-state autorotation segments after power failure of a helicopter. In order to solve the technical problems, the invention provides the following technical scheme: In a first aspect, the embodiment of the invention provides a real-time track planning method for a steady-state autorotation segment after power failure of a helicopter, which comprises initializing a system and reading state information of the current helicopter as initial point state information; the method comprises the steps of calculating a landing point reaching area according to initial point state information, namely a pre-landing point maximum distribution area capable of realizing safe landing operation through a self-rotation downslide flight mode, selecting a safe and barrier-free target landing point and expected landing course angle in the displayed reaching area by a driver or an automatic system, setting the ideal entering speed and the ideal entering height of a ne