Unmanned aerial vehicle autonomous landing strategy based on holder visual servo in GNSS-free environment

Abstract

The invention discloses an unmanned aerial vehicle autonomous landing strategy based on holder visual servo in a GNSS-free environment, and the strategy comprises a rapid landing method, a navigation method and a system control method, and the rapid landing method comprises the following steps: an unmanned aerial vehicle firstly cruises according to a specified track; searching a point capable of normally receiving a GPS signal as a landing starting point of the unmanned aerial vehicle, once receiving an enough reliable signal, comparing absolute position information of the unmanned aerial vehicle and the landing point by the unmanned aerial vehicle, determining an initial relative position between the unmanned aerial vehicle and the landing point, and then starting to land; in order to ensure that the unmanned aerial vehicle can return and land in an environment without GNSS signals, the method uses a visual system to track the landing point of the unmanned aerial vehicle and calculate the real-time position of the unmanned aerial vehicle; the unmanned aerial vehicle simultaneously moves in the horizontal and vertical directions, so that the landing time is shortened, and the landing success rate is improved; compared with a traditional unmanned aerial vehicle landing scheme, the landing system has higher landing success rate and landing precision and shorter landing time.

Description

technical field [0001] The invention belongs to the technical field of unmanned aerial vehicles, and in particular relates to an autonomous landing strategy of an unmanned aerial vehicle based on a pan-tilt visual servo in a non-GNSS environment. Background technique [0002] Unmanned Aerial Vehicle (UAV) is widely used in various dangerous or inaccessible places due to its advantages of simple operation and convenient take-off and landing. UAVs are often used as equipment in the fields of environmental monitoring, terrain exploration, military strikes, emergency communications, search and rescue operations, etc. Although drones are controlled by manual remote control, due to high labor costs and limited cruising distance, the control mode of drones is gradually shifting to autonomous flight mode. [0003] As the end of UAV autonomous cruise, autonomous landing plays an important role in UAV autonomous flight. Most traditional landing systems use motion capture systems, gl...

AI Technical Summary

Problems solved by technology

However, due to the existence of accumulated errors, this navigation system will drift during long-term flight. Therefore, we propose an autonomous landing strategy for UAVs based on gimbal visual servo in a non-GNSS environment.

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