Design of automatic take-off control strategy for a small unmanned helicopter

Abstract

An automatic take-off control strategy for a small unmanned helicopter, which includes the following steps: 1. Judging whether to respond to a take-off command; Latitude, altitude and yaw angle information and calculate the average value; 3. If the above step 2 determines that the engine speed is stable, the collective distance will increase at a certain rate; 4. If the above step 3 determines that the collective distance reaches the pre-ground collective distance, then The helicopter applies plane position and attitude control, and the collective distance continues to increase until the helicopter lifts off the ground; 5. If the above step 4 confirms that the helicopter is off the ground, update the collective distance trim value and call the vertical channel control law until it approaches the set take-off altitude; 6. If the above step 5 determines that it is close to the set take-off altitude, the fixed-point hovering control law is invoked, and the take-off ends. The invention can improve the automatic take-off capability of the small unmanned helicopter, enhance its application range, and has low complexity and high reliability.

Description

technical field [0001] The invention relates to an automatic take-off control strategy of a small unmanned helicopter. By designing the take-off process and transition strategy of the unmanned helicopter, the automatic take-off of the unmanned helicopter is realized, and belongs to the field of autonomous control of the small unmanned helicopter. Background technique [0002] A UAV is an aircraft that is controlled by radio or ground station systems and made to fly autonomously in accordance with predetermined procedures without a human driver. Compared with manned aircraft, it has significant advantages such as small size, low cost, long working hours, and can operate in dangerous and complex environments. Compared with fixed-wing aircraft, unmanned helicopters have the ability to hover in the air and move in any direction. It has the advantages of flying, ultra-low altitude and low-speed flight, and more importantly, it does not need a landing platform and a flight runway,...

AI Technical Summary

Problems solved by technology

[0006] The second is that the automatic take-off of the helicopter needs to switch between two states. The helicopter has to enter the air flight state from the state of staying on the ground. The constraints on the helicopter in these two states are completely different. stable state, while the helicopter is a six-degree-of-freedom moving object when it is flying in the air, and it is in an unstable state, and the trim attitude of the helicopter in the air is different from the state on the ground. turn

[0007] The third is that the helicopter is affected by the ground effect in the near-ground stage, and the airflow is extremely unstable, which may easily cause the helicopter to slip, which in turn will cause a drastic change in the attitude of the helicopter, resulting in unilateral or single-point landing of the helicopter landing gear.

[0008] Fourth, since unmanned helicopters generally use GPS and other satellite navigation system sensors for position positioning, the positioning accuracy of the sensors will be reduced near the ground due to the influence of ground clutter, trees and buildings.

Images