Emergency return landing speed command set design method

Abstract

The invention belongs to a field of flight control technology and discloses an emergency return landing speed command set design method. The method includes (1), constructing a grid of mass, rolling angle, airport height, height and speed parameters, calculating an attack angle, an elevator, a lift-drag ratio, a track angle and a submerge rate of constant speed gliding of an aircraft, determining the maximal lift-drag ratio rate and the idle gliding maximal available speed changing along with mass, rolling angle, airport height and height, dividing a speed range between the maximal lift-drag ratio rate and the idle gliding maximal available speed into N+1 parts, adding the maximal lift-drag ratio rate and the idle gliding maximal available speed for creating a N+2 grade speed command set, wherein the content of each grade of the speed command set includes the attack angle, the elevator, the lift-drag ratio, the track angle and the submerge rate corresponding to the speed of said grade; (3) recording the N+2 grade speed command set by the aircraft, and selecting an appropriate speed command set grade for execution according to the mass, the airport height, the height, the speed and the distance between the aircraft and the airport when emergency aircraft return landing is required.

Description

technical field [0001] The invention belongs to the flight control technology, and in particular relates to an autonomous guidance and control technology for an aircraft without power to return to the field and land. Background technique [0002] When the aircraft has an engine shutdown failure in the air, the performance of the aircraft is degraded and it can only fly downhill. In order to ensure flight safety, it is necessary to control the speed of the aircraft and modify the flight trajectory to avoid stalling caused by excessive trajectory pull-up. At the same time, the lift-to-drag ratio of the aircraft glide can be adjusted to land the aircraft on the airport runway as much as possible. The literature "Design of Emergency Landing Control Law for Wheeled Take-off and Landing UAVs" provides a difficult analysis and solution to the problem of idling back and landing: 1) In the transitional flight phase, use the maximum lift-to-drag ratio speed to glide to maximize The f...

AI Technical Summary

Problems solved by technology

However, when it is applied to engineering practice, it lacks the consideration of the following three issues: 1) In the process of idling return, the engine must be started in the air, and gliding with the maximum lift-to-drag ratio may not be able to reach the speed condition of the engine idling; 2) If the maximum lift-to-drag ratio speed is used to descend, the flying speed should be relatively low within the flying speed range. Compared with other speeds, the flying distance and time are relatively long, and the battery may be exhausted before the aircraft slides to the airport. Still unable to land safely

3) The conditions for the engine to stop in the air are uncertain. For the parking situation at the same height but with different distances and energy states, the actual flight distance is almost the same, and the glide speed strategy is not flexible enough

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