Helicopter atmospheric data system and atmospheric parameter measurement method thereof

Abstract

The application discloses a helicopter atmospheric data system and an atmospheric parameter measuring method thereof, and belongs to the technical field of atmospheric data measurement. The helicopter atmospheric data system comprises a fixed total static pressure probe, a follow-up multifunctional static pressure probe and an atmospheric data processing module which are electrically connected with each other. The fixed total static pressure probe is arranged on the surface of the head end of the helicopter body through a fixed support. The follow-up multifunctional static pressure probe is arranged on the surface of the head end of the helicopter body through a follow-up support. The atmospheric data processing module is integrated in the helicopter control system. The fixed total static pressure probe and the follow-up multifunctional static pressure probe are arranged on the helicopter body respectively, and are used for measuring different flight states of the helicopter respectively. The atmospheric data processing module is used for real-time calculation. The accurate measurement of the airspeed of the helicopter is realized. The calculated airspeed is sent to the airspeed meter and other equipment in the helicopter, so that the operator can check in time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air data measurement, in particular to a helicopter air data system and an air parameter measurement method thereof. BACKGROUND

[0002] The helicopter belongs to the rotorcraft, the rotation axis of the rotor is approximately vertical, and the upward lift is generated by the rotation, and the horizontal component forces in the front, back, left and right directions can be generated by special devices, so that the helicopter can fly in any direction. Therefore, the helicopter can take off vertically, hover and fly in any direction, which is very different from the fixed-wing aircraft. The rotor is the key component of the helicopter, and its movement characteristics have a significant impact on the entire helicopter flow field, thereby causing a huge difference in the flow field of the fixed-wing aircraft. First, due to the rotational motion of the rotor, the different positions of the blades have different linear velocities, and there are usually transonic speeds at the blade tips and incompressible flow regions near the hub; second, each blade of the rotor drags a strong and concentrated contraction and spiral development of the tip vortex and vortex surface, which is not dispersed until a long distance downstream, and these vortices dominate the entire rotor flow field. These make the entire flow field very complex. At the same time, the helicopter rotor also has special movements such as flapping, flapping, periodic moment change and total distance change, which make the entire flow field very complex.

[0003] Therefore, the helicopter widely adopts the fixed full pressure pipe + fuselage static pressure hole, or the total static pressure sensor, which cannot be used when disturbed by the rotor, and almost has no ability to measure airspeed under low speed conditions. To solve this problem, a helicopter three-axis air data system is developed, which uses a three-axis velocity vector sensor installed on a mounting bracket extending a certain distance outside the fuselage. The total pressure, static pressure and airflow angle of the combined airflow of the flight airflow, rotor downwash flow and wind speed can be sensed through the rotating airspeed tube, and the algorithm model and real flight model are adjusted to ultimately obtain air parameter information. However, the three-axis air data system must be extended through the mounting rod, and the structure is complex. At the same time, it must be adjusted and corrected by a large amount of flight data, and its application is greatly limited, only used on high-end military helicopters. At the same time, under very low speed conditions, it is still unable to measure. SUMMARY

[0004] In view of the problems existing in the prior art, the present application provides a helicopter air data system and an air parameter measurement method thereof, which solves the problem that the existing helicopter air data system cannot measure air parameters under low speed conditions of the helicopter.

[0005] In order to achieve the above-mentioned application purposes, the technical scheme adopted by the present application is as follows:

[0006] Provided is a helicopter atmospheric data system, comprising a fixed total pitot probe, a follow-up multifunctional pitot probe and an atmospheric data processing module in electrical connection with each other;

[0007] The fixed total pitot probe is arranged on the surface of the head end of the helicopter body through a fixed support and is used to measure the total pressure and static pressure of the atmosphere.

[0008] The follow-up multifunctional pitot probe is arranged on the surface of the head end of the helicopter body through a follow-up support and is used to measure the total pressure and static pressure of the atmosphere at multiple angles.

[0009] The atmospheric data processing module is integrated into the helicopter control system.

[0010] Further, the follow-up support comprises a base fixedly connected with the surface of the head end of the helicopter body, a rotating shaft vertically arranged on the base, a follow-up rod arranged on the top of the rotating shaft, the top of the rotating shaft fixedly connected with the middle part of the follow-up rod, the follow-up multifunctional pitot probe arranged on one end of the follow-up rod, and an angle-of-attack wind vane fixedly arranged on the other end of the follow-up rod, the plane of the angle-of-attack wind vane being parallel to the plane formed by the axis of the rotating shaft and the axis of the follow-up rod.

[0011] Further, the base is in the shape of a circular truncated cone, a plurality of mounting holes for fixedly connecting with the surface of the helicopter body are arranged on the base, and the plurality of mounting holes are evenly arranged in a ring shape around the axis of the base.

[0012] The application further provides an atmospheric parameter measurement method for the helicopter atmospheric data system, which comprises the following steps:

[0013] The airspeed calculation formula of the fixed total pitot probe is as follows:

[0014] Pt 固 = 0.5 ρV 固 2 + Ps

[0015] wherein Pt 固 is the total pressure measured by the fixed total pitot probe, Ps is the static pressure measured by the fixed total pitot probe, and ρ is the air density.

[0016] The airspeed calculation formula of the total pressure of the follow-up multifunctional pitot probe is as follows:

[0017] Pt 动 = 0.5 ρV 动 2 + Ps

[0018] wherein Pt 动 is the total pressure of the follow-up multifunctional pitot probe, Ps is the static pressure measured by the fixed total pitot probe, and ρ is the air density.

[0019] When flying at high speed, the helicopter body can be considered not to be affected by the downwash flow of the rotor, or the speed component of the downwash flow is too small to be ignored; at this time, the follow-up multifunctional static pressure probe outputs the local angle of attack value α and the total pressure value, the fixed total static pressure probe outputs the total pressure value, and the two total pressure values are the same; at this time:

[0020] V 固 =V 动 ;

[0021] The atmospheric data processing module outputs V 指示 =V 固 , wherein V 指示 is the indicated airspeed output to the airspeed indicator in the helicopter and the matched total static pressure probe system, V 固 is the airspeed calculated by the fixed total static pressure probe, and V 动 is the airspeed calculated by the follow-up multifunctional static pressure probe.

[0022] When the helicopter hovers, the follow-up multifunctional static pressure probe outputs the total pressure value and the angle of attack value, the fixed total static pressure probe outputs the total pressure value, at this time, the total pressure value output by the fixed total static pressure probe is even lower than the static pressure value of the fixed total static pressure probe, and thus is invalid; and the angle of attack value α of the follow-up multifunctional static pressure probe is 90°, that is, the angle of attack wind vane is vertically upward, the atmospheric data processing module outputs V 指示 =V 动 cos 90° = 0.

[0023] When the helicopter flies forward at very low speed, the follow-up multifunctional static pressure probe outputs the total pressure value and the angle of attack value, the fixed total static pressure probe outputs the total pressure value, at this time, the total pressure value output by the fixed total static pressure probe is even lower than the static pressure value of the fixed total static pressure probe, and thus is invalid; and the angle of attack value α of the follow-up multifunctional static pressure probe is 20-90° after correction, the atmospheric data processing module outputs V 指示 =V 动 cos α.

[0024] When the helicopter flies forward normally, at this time, the follow-up multifunctional static pressure probe outputs the total pressure value and the angle of attack value, the fixed total static pressure probe outputs the total pressure value, and the angle of attack value α of the follow-up multifunctional static pressure probe is less than 20° after correction, the atmospheric data processing module outputs V 指示 =V 固 .

[0025] The beneficial effects of the present application are: 1. The helicopter atmospheric data system and the atmospheric parameter measurement method thereof, the fixed total pressure probe and the follow-up multifunctional static pressure probe are arranged on the helicopter body respectively, the fixed total pressure probe and the follow-up multifunctional static pressure probe are used for measuring different flight states of the helicopter respectively, and the atmospheric data processing module is used for real-time solving, so that the accurate measurement of the airspeed of the helicopter is realized, and the solved airspeed is sent to the airspeed meter and other equipment in the helicopter, so that the operator can check in time.

[0026] 2. The helicopter atmospheric data system and the atmospheric parameter measurement method thereof, the follow-up multifunctional static pressure probe rotates with the helicopter to provide an angle of attack measurement function.

[0027] 3. The helicopter atmospheric data system and the atmospheric parameter measurement method thereof, compared with the traditional pitot tube measurement airspeed and three-axis atmospheric data system, the helicopter low-speed forward flight problem of the traditional pitot tube measurement airspeed precision is solved, at the same time, the probe does not need to be stretched out outside the body, the structure is simple, and the applicability is strong. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a structural schematic view of a helicopter atmospheric data system.

[0029] Figure 2 It is a structural schematic view of a follow-up support.

[0030] Among them, 1, fixed total pressure probe; 2, follow-up multifunctional static pressure probe; 3, fixed support; 4, follow-up support; 401, base; 402, rotating shaft; 403, follow-up rod; 404, angle of attack wind vane; 405, mounting hole; 5, helicopter body. DETAILED DESCRIPTION

[0031] The specific embodiments of the present application are described below, so that those skilled in the art can understand the present application, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the appended claims, these changes are obvious, and all the inventions using the concept of the present application are within the scope of protection.

[0032] As Figures 1-2 shown, the present application provides a helicopter atmospheric data system, which comprises a fixed total pressure probe 1, a follow-up multifunctional static pressure probe 2 and an atmospheric data processing module which are electrically connected to each other;

[0033] The fixed full static pressure probe 1 is set on the surface of the head end of the helicopter fuselage 5 through a fixed bracket 3, and is used to measure the total atmospheric pressure and static pressure; the follow-up multifunctional static pressure probe 2 is set on the surface of the head end of the helicopter fuselage 5 through a follow-up bracket 4, and is used to measure the total atmospheric pressure and static pressure from multiple angles; the atmospheric data processing module is integrated into the helicopter control system.

[0034] By respectively arranging a fixed full static pressure probe 1 and a follow-up multifunctional static pressure probe 2 on the helicopter fuselage 5, the fixed full static pressure probe 1 and the follow-up multifunctional static pressure probe 2 are used to measure different flight states of the helicopter, and perform real-time calculations through the atmospheric data processing module to achieve accurate measurement of the helicopter airspeed, and the calculated airspeed is sent to the airspeed meter and other equipment in the helicopter for the operator to check in time.

[0035] Specifically, as a specific setting method of the follower bracket 4, the follower bracket 4 includes a base 401 fixedly connected to the surface at the head end of the helicopter fuselage 5, a rotating shaft 402 is vertically arranged on the base 401, a follower rod 403 is arranged on the top of the rotating shaft 402, and the top of the rotating shaft 402 is fixedly connected to the middle part of the follower rod 403, one end of the follower rod 403 is provided with the follower multifunctional static pressure probe 2, and the other end is fixedly provided with an angle of attack wind vane 404, and the plane where the angle of attack wind vane 404 is located is parallel to the plane formed by the axis of the rotating shaft 402 and the axis of the follower rod 403.

[0036] When the helicopter is in different flight states, the angle of attack wind vane 404 is affected by wind flows at different angles, driving the follow-up multifunctional static pressure probe 2 on the rotating shaft 402 to rotate, thereby enabling the follow-up multifunctional static pressure probe 2 to rotate with the helicopter and provide angle of attack measurement function.

[0037] Furthermore, the base 401 is a truncated cone structure, and is provided with a plurality of mounting holes 405 for fixedly connecting to the surface of the helicopter fuselage 5 . The plurality of mounting holes 405 are evenly spaced in a circumferential direction around the axis of the base 401 .

[0038] The present invention also provides a method for measuring atmospheric parameters of a helicopter atmospheric data system, which comprises:

[0039] The airspeed calculation formula for the fixed full static pressure probe 1 is:

[0040] Pt 固 =0.5ρV 固 2 +Ps;

[0041] Among them, Pt 固 is the total pressure measured by the fixed full static pressure probe 1, Ps is the static pressure measured by the fixed full static pressure probe 1, and ρ is the air density;

[0042] The airspeed calculation formula of the follow-up multifunctional static pressure probe 2 total pressure is:

[0043] Pt 动 = 0.5pV 动 2 + Ps;

[0044] Wherein, Pt 动 is the follow-up multifunctional static pressure probe 2 total pressure, Ps is the fixed total static pressure probe 1 measured static pressure, and p is the air density;

[0045] When flying at high speed, it can be considered that the helicopter body is not affected by the downwash airflow of the rotor, or the speed component of the downwash is too small to be ignored; at this time, the follow-up multifunctional static pressure probe 2 outputs the local angle of attack value a and the total pressure value, the fixed total static pressure probe 1 outputs the total pressure value, and the two total pressure values are the same; at this time:

[0046] V 固 = V 动 ;

[0047] The atmospheric data processing module outputs V 指示 = V 固 , wherein V 指示 is the indicated airspeed output to the airspeed indicator in the helicopter and the matched total static pressure probe system, V 固 is the airspeed calculated by the fixed total static pressure probe 1, and V 动 is the airspeed calculated by the follow-up multifunctional static pressure probe 2;

[0048] When the helicopter hovers, the follow-up multifunctional static pressure probe 2 outputs the total pressure value and the angle of attack value, and the fixed total static pressure probe 1 outputs the total pressure value; at this time, the total pressure value output by the fixed total static pressure probe 1 is even lower than the static pressure value of the fixed total static pressure probe 1, so it is invalid; and the angle of attack value a of the follow-up multifunctional static pressure probe 2 is 90°, that is, the angle of attack wind vane 404 is vertically upward, and the atmospheric data processing module outputs V 指示 = V 动 cos 90° = 0;

[0049] When the helicopter flies forward at very low speed, the follow-up multifunctional static pressure probe 2 outputs the total pressure value and the angle of attack value, and the fixed total static pressure probe 1 outputs the total pressure value; at this time, the total pressure value output by the fixed total static pressure probe 1 is even lower than the static pressure value of the fixed total static pressure probe 1, so it is invalid; and when the angle of attack value a of the follow-up multifunctional static pressure probe 2 is corrected to 20-90°, the atmospheric data processing module outputs V 指示 = V 动 cos a;

[0050] When the helicopter is normally forward flying, at this time, the follow-up multifunctional static pressure probe 2 outputs the total pressure value and the attack angle value, the fixed total static pressure probe 1 outputs the total pressure value, and when the attack angle value α of the follow-up multifunctional static pressure probe 2 is less than 20° after correction, the atmospheric data processing module outputs V 指示 = V 固 .

[0051] In summary, the helicopter atmospheric data system and the atmospheric parameter measurement method thereof solve the problem of insufficient accuracy of the conventional pitot tube in measuring airspeed when the helicopter is forward flying at low speed, and meanwhile, the probe does not need to be extended far outside the fuselage, so that the structure is simple and the applicability is strong.

Claims

1. A method for measuring atmospheric parameters of a helicopter air data system, characterized in that: The helicopter atmospheric data system includes a fixed full static pressure probe, a follow-up multifunctional static pressure probe, and an atmospheric data processing module electrically connected to each other; the fixed full static pressure probe is mounted on the surface of the helicopter fuselage head end via a fixed bracket for measuring atmospheric total pressure and static pressure; the follow-up multifunctional static pressure probe is mounted on the surface of the helicopter fuselage head end via a follow-up bracket for measuring atmospheric total pressure and static pressure at multiple angles; and the atmospheric data processing module is integrated into the helicopter control system; The follower bracket includes a base fixedly connected to the surface at the head end of the helicopter fuselage, a rotating shaft is vertically provided on the base, a follower rod is provided on the top of the rotating shaft, the top of the rotating shaft is fixedly connected to the middle part of the follower rod, one end of the follower rod is provided with the follower multifunctional static pressure probe, and the other end is fixedly provided with an angle of attack wind vane, and the plane where the angle of attack wind vane is located is parallel to the plane formed by the axis of the rotating shaft and the axis of the follower rod; the base is a frustum structure, and a plurality of mounting holes for fixed connection to the surface of the helicopter fuselage are provided on the base, and the plurality of mounting holes are evenly spaced in a circumferential direction around the axis of the base; The atmospheric parameter measurement method comprises: The airspeed calculation formula for a fixed full static pressure probe is: Pt 固 =0.5ρV 固 2 +Ps1; Among them, Pt 固 is the total pressure measured by the fixed full static pressure probe, Ps1 is the static pressure measured by the fixed full static pressure probe, and ρ is the air density; The calculation formula for the airspeed of the full pressure of the follow-up multi-function static pressure probe is: Pt 动 =0.5ρV 动 2 +Ps2; Among them, Pt 动 is the total pressure of the follow-up multi-function static pressure probe, Ps2 is the static pressure measured by the follow-up multi-function static pressure probe, and ρ is the air density; When flying at high speed, it can be assumed that the helicopter body is not affected by the rotor downwash, or the velocity component of the downwash is too small to be ignored. At this time, the follow-up multi-function static pressure probe outputs the local angle of attack value α and the total pressure value, and the fixed total static pressure probe outputs the total pressure value. The two total pressure values ​​are the same. At this time: V 固 =V 动 ; Atmospheric data processing module output V 指示 =V 固 , where V 指示 V is the indicated airspeed output to the airspeed indicator in the helicopter and its supporting full static pressure probe system. 固 is the airspeed calculated by the fixed total static pressure probe; V 动 The airspeed calculated by the follow-up multi-function static pressure probe; When the helicopter is hovering, the follow-up multifunctional static pressure probe outputs the total pressure value and the angle of attack value, and the fixed total static pressure probe outputs the total pressure value. At this time, the total pressure value output by the fixed total static pressure probe is even lower than the static pressure value of the fixed total static pressure probe, so it is invalid; and the angle of attack value α of the follow-up multifunctional static pressure probe is 90°, that is, the angle of attack wind vane is vertically upward, and the atmospheric data processing module outputs V 指示 =V 动 cos90°=0; When the helicopter flies forward at an extremely low speed, the follow-up multi-function static pressure probe outputs the total pressure value and the angle of attack value, and the fixed full static pressure probe outputs the total pressure value. At this time, the total pressure value output by the fixed full static pressure probe is even lower than the static pressure value of the fixed full static pressure probe, so it is invalid; and when the angle of attack value α of the follow-up multi-function static pressure probe is corrected to 20~90°, the atmospheric data processing module outputs V 指示 =V 动 cosα; When the helicopter is flying forward normally, the follow-up multifunctional static pressure probe outputs the total pressure value and the angle of attack value, the fixed total static pressure probe outputs the total pressure value, and the angle of attack value α of the follow-up multifunctional static pressure probe is less than 20° after correction, the atmospheric data processing module outputs V 指示 =V 固 .

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