Method for realizing GS gliding function of helicopter three-axis flight control system

Abstract

The invention discloses a method for realizing the GS gliding function of a helicopter three-axis flight control system. The method comprises the following steps that: step 1, when one of the following two conditions is satisfied, the GS function belongs to a ready state but a helicopter is not controlled; the condition 1 is as follows: an LOC function of a flight control system is in a ready state; the condition 2 is as follows: the LOC function of the flight control system is in an interception or tracking state, the deviation beta of a glide slope is greater than 0.5 dot, and the radio height is greater than 100ft; step 2, when the following two conditions are met at the same time, the GS function belongs to an interception state, and the pitch axis of the helicopter is controlled to fly along the glide slope at a preset angle of an airport; the condition 1 is as follows: the LOC function of the flight control system is in an interception or tracking state; the condition 2 is as follows: the glide slope deviation beta is less than or equal to 0.5 dot and the radio height is greater than 100 ft; and step 3, when the radio height on the helicopter is reduced to 100ft, the GS function of the flight control system is automatically converted from gliding to level flight, and finally, the radio height reference is kept at 80ft.

Description

Technical field [0001] The invention belongs to the technical field of automatic flight control of aerospace vehicles, and relates to a method for implementing the GS glide function of a helicopter three-axis flight control system. Background technique [0002] In the field of civil aviation, the airport will establish an ILS instrument landing system on one side of the runway, which contains the LOC channel signal aligned to the centerline of the runway, the GS glide signal indicating the landing angle of the aircraft, and the distance signal from the runway entrance. The gliding signal can guide the helicopter to descend height along a fixed-angle glideslope, and then manually control the landing in a low-altitude level flight state. [0003] Generally, the four-axis automatic flight control system uses the collective pitch axis to control the aircraft's descending altitude along the glide path, and the pitch axis to control the airspeed, so as to achieve the altitude reduction u...

AI Technical Summary

Problems solved by technology

However, the three-axis automatic flight control system has no collective axis, so it can only control the helicopter to lower its head through the pitch axis to achieve the height of descent, and the helicopter will gradually increase the speed of descent when flying with its head lowered.

When the helicopter changes from the gliding state to the 80ft reference altitude holding state at the radio altitude of 100ft, the difference of 20ft and the large lifting speed lead to a greater control effect of the pitch axis, resulting in a large first-time overshoot, and the altitude holding accuracy is not high.

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