Helicopter flight state identification methodTechnical Field
The invention belongs to the technical field of helicopter flight state identification, and particularly relates to a helicopter flight state identification method.
Background
The identification of the flight state of the helicopter is very important to the analysis of helicopter test flight data, helicopter fault diagnosis and life prediction. The existing published documents have the defects of poor recognition effect and the like caused by higher input dimension, complex calculation process and difficult convergence of a network model, which are caused by a dynamic method, an image analysis method, a neural network method and a flight state recognition method based on a support vector machine.
The invention designs a helicopter flight state identification device, which is used for identifying each flight state of a helicopter based on a flight state identification logic tree, and displaying identification results through different ground colors.
Disclosure of Invention
The purpose of the invention is that: a helicopter flight state identification method is designed to solve the technical problems of higher input dimension and complex calculation process in the existing identification method.
In order to solve the technical problem, the technical scheme of the invention is as follows:
the helicopter flight state identification method is characterized in that the helicopter flight state identification method utilizes a flight state identification logic tree to judge the flight state of a helicopter, and the flight state identification logic tree utilizes the following flight parameters to judge in real time: pressure altitude, atmospheric temperature, indicated airspeed, GPS north speed, GPS east speed, magnetic heading angle, ground altitude, ground zero point, roll angle, engine torque, number of engines, vertical overload.
The helicopter flight state identification method specifically comprises the following steps:
step one, judging whether the ground state is an air flight or not according to the ground clearance;
judging AEO, OEI and autorotation states of the helicopter according to the engine torque and the number of engines;
step three, judging whether the helicopter is in a hovering state or a flying state according to the GPS horizontal speed;
if the helicopter is in a hovering state, judging the pointing change rate of the machine head and the change rate of the ground clearance height, and judging whether the helicopter is hovering maneuver or hovering with/without ground effect;
if the vehicle is in a flying state, entering a fourth step;
judging whether the helicopter is in a forward flight state, a left side flight state, a right side flight state or a rear flight state according to the GPS horizontal speed and the magnetic heading angle;
if the helicopter is in a forward flight state, entering a step five;
fifthly, judging whether the helicopter is in a stable flight or a maneuvering flight state through vertical overload;
if the helicopter is in a stable flight state, entering a step six;
step six, judging whether the helicopter is in a flat flight, climbing or descending state according to the pressure altitude change rate;
if the helicopter is in a flat flight state, entering a step seven;
step seven, judging whether the helicopter is in an accelerating state, a decelerating state or a constant-speed flat flight state according to the flat flight speed change rate;
if the speed is in the constant speed flat flight state, entering a step eight;
and step eight, judging whether the helicopter is in a flat flight turning state or a stable flat flight state according to the roll angle.
The specific judging process in the first step is as follows:
and deducting the ground clearance point to obtain the actual ground clearance height through the measured ground clearance height of the helicopter, and judging whether the helicopter is lifted off the ground according to whether the actual ground clearance height is greater than 0.
And step three, the GPS horizontal speed is calculated by the GPS north speed and the GPS east speed.
And thirdly, calculating the pointing change rate and the ground clearance height change rate of the machine head through a magnetic heading angle and a pressure height.
And step seven, the flat flying speed change rate is obtained through calculation of a vacuum speed.
The vacuum speed is calculated by indicating airspeed, atmospheric static temperature and pressure altitude.
In another implementation, the ground clearance height may be replaced with a pressure height, and a corresponding ground clearance zero point initial value is set.
Preferably, the helicopter ground clearance in step one is measured by a radio altimeter or a laser altimeter.
The beneficial effects of the invention are as follows:
the helicopter flight state identification method can be used for identifying helicopter flight parameter data, selecting test flight data and the like, and a user can quickly position a required data segment according to the flight state identification result, so that convenience and rapidness are realized; the actual service condition of each helicopter is counted by analyzing the time duty ratio of each flight state of the helicopter, and accurate data sources are provided for the residual life evaluation and maintenance guarantee plan of each part of the helicopter.
The helicopter flight state recognition method based on the invention can develop a recognition device, based on flight test data recorded on the helicopter, the flight state of the helicopter is judged in real time through the flight state recognition logic tree, and the helicopter flight state is displayed through different ground colors, so that a user can conveniently and quickly recognize the flight state of the helicopter, and the helicopter flight state recognition method based on the invention has the advantages of real time, accuracy, convenience and the like.
Drawings
In order to more clearly illustrate the technical solution of the implementation of the present invention, the following description will briefly explain the drawings that need to be used in the examples of the present invention. It is evident that the drawings described below are only some embodiments of the invention and that other drawings may be obtained from these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a logic diagram of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making any inventive effort are intended to fall within the scope of the present invention.
Features of various aspects of embodiments of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The following description of the embodiments is merely for a better understanding of the invention by showing examples of the invention. The present invention is not limited to any particular arrangement and method provided below, but covers any modifications, substitutions, etc. of all product constructions, methods, and the like covered without departing from the spirit of the invention.
Well-known structures and techniques have not been shown in detail in the various drawings and the following description in order not to unnecessarily obscure the present invention. Table 1 below is a table of the flight status of a helicopter, wherein the different status shows different status ground colors on the dashboard.
TABLE 1
| Sequence number | Flight status | Status ground color |
| 1 | Ground state | Black color |
| 2 | With/without ground effect hover | Blue light |
| 3 | Hover maneuver | Water green |
| 4 | Fly to the left and right | Red colour |
| 5 | Reverse flying | Red colour |
| 6 | Climbing up | Yellow colour |
| 7 | Descent down | Orange with a color of white |
| 8 | Fly flat turning | Green, green |
| 9 | Acceleration and deceleration plane fly | Pink red |
| 10 | Stabilize plane and fly | Blue-green |
| 11 | Flying maneuver | Red colour |
| 12 | OEI flight | Red colour |
| 13 | Self-rotation | Red colour |
As shown in fig. 1, which is a logic diagram of the helicopter flight status recognition method of the invention, the flight status recognition logic tree performs real-time judgment by using the following flight parameters: pressure altitude, atmospheric temperature, indicated airspeed, GPS north speed, GPS east speed, magnetic heading angle, ground altitude, ground zero point, roll angle, engine torque, number of engines, vertical overload. Table 2 below shows the status recognition parameters of the helicopter flight records required for the recognition method of the present invention,
TABLE 2
The method for real-time judgment by utilizing the identification logic tree comprises the following specific steps:
step one, judging whether the ground state is an air flight or not according to the ground clearance;
the ground clearance of the helicopter measured by the radio high-speed instrument or the laser altimeter is deducted to obtain the actual ground clearance, whether the helicopter is lifted off or not is judged by judging whether the actual ground clearance is larger than 0, and whether the helicopter is lifted down or not when flying flatly or hovering near the ground is also judged. Pressure altitude substitution may be used in the absence of ground altitude data, but a corresponding ground zero point needs to be set.
Judging AEO, OEI and autorotation states of the helicopter according to the engine torque and the number of engines;
and judging whether each engine torque is greater than a certain threshold value or not to judge whether the engine is in a normal working state or a failure state. If the torque of each engine is greater than a certain threshold value, the helicopter is in an AEO flight state; if the torque value of one engine is smaller than or equal to a certain threshold value, the helicopter is in an OEI flight state; if the torque values of all the engines are smaller than or equal to a certain threshold value, the helicopter is in a autorotation state;
step three, judging whether the helicopter is in a hovering state or a flying state according to the GPS horizontal speed;
if the helicopter is in a hovering state, judging the pointing change rate of the machine head and the change rate of the ground clearance height, and judging whether the helicopter is hovering maneuver or hovering with/without ground effect;
the GPS horizontal speed is obtained by calculating the GPS north speed and the GPS east speed; the machine head pointing change rate and the ground clearance change rate are obtained through calculation of a magnetic heading angle and the ground clearance.
The machine head pointing change rate is obtained through differential calculation of a magnetic heading angle; the change rate of the ground clearance is obtained through differential calculation of the ground clearance. If the machine head pointing change rate is less than or equal to a certain threshold value and the ground clearance height change rate is less than or equal to a certain threshold value, the machine head is hovered with or without ground effect, otherwise, the machine head is hovering maneuver.
If the vehicle is in a flying state, entering a fourth step;
judging whether the helicopter is in a forward flight state, a left side flight state, a right side flight state or a rear flight state according to the GPS horizontal speed and the magnetic heading angle;
if the helicopter is in a forward flight state, entering a step five;
fifthly, judging whether the helicopter is in a stable flight or a maneuvering flight state through vertical overload;
if the helicopter is in a stable flight state, entering a step six;
step six, judging whether the helicopter is in a flat flight, climbing or descending state according to the pressure altitude change rate;
if the helicopter is in a flat flight state, entering a step seven;
step seven, judging whether the helicopter is in an accelerating state, a decelerating state or a constant-speed flat flight state according to the flat flight speed change rate;
the flat flying speed change rate is obtained through vacuum speed calculation. The vacuum velocity is calculated by indicating airspeed, atmospheric static temperature, and pressure altitude. The flat fly rate of change is calculated by vacuum velocity differential,
where k and b are obtained by airspeed calibration pilot runs. Rate of change of speed if level>A certain threshold value 1, the helicopter is in an acceleration state; rate of change of speed if level<A certain threshold value 2, the helicopter is in a deceleration state; if the change rate of the speed of the flat flight is less than or equal to a certain threshold value 2 and less than or equal to a certain threshold value 1, the helicopter is in a constant-speed flat flight state.
If the speed is in the constant speed flat flight state, entering a step eight;
and step eight, judging whether the helicopter is in a flat flight turning state or a stable flat flight state according to the roll angle.
In the method, the pressure height can be used for replacing the ground clearance height, and the initial value of the ground clearance zero point corresponding to the pressure height is set.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered in the scope of the present invention.