CN-116820151-B - IMU-free posture adjustment method and system applied to unmanned aerial vehicle holder

CN116820151BCN 116820151 BCN116820151 BCN 116820151BCN-116820151-B

Abstract

The invention discloses an IMU-free posture adjustment method and system applied to an Unmanned Aerial Vehicle (UAV) holder, wherein the method comprises the steps that the holder controls postures through a plurality of servo motors, and angle encoders are arranged on output shafts of the servo motors; the method comprises the steps of obtaining a range A of an attitude angle of an unmanned aerial vehicle, obtaining an encoder value B of an angle encoder corresponding to the range A, establishing a conversion relation between the encoder value B and the attitude angle of the unmanned aerial vehicle, establishing communication between a cradle head and the unmanned aerial vehicle in flight, obtaining the variation of the attitude angle of the unmanned aerial vehicle in real time, converting the variation into the variation of the corresponding encoder value according to the conversion relation, and adjusting the attitude of the cradle head by a servo motor according to the obtained variation of the encoder value. The invention is applied to the IMU-free posture adjustment method and system of the Unmanned Aerial Vehicle (UAV) tripod head, the tripod head increment of the electronic stability augmentation device is eliminated, the tripod head stability augmentation is realized by controlling the relative position of the UAV, and the problem of mismatching of encoder data and posture data is solved by means of normalization and analogy.

Inventors

ZHANG XIUSONG
JIN GANG

Assignees

上海舆芯半导体科技有限公司

Dates

Publication Date: 20260505
Application Date: 20230718

Claims (5)

1. An IMU-free posture adjustment method applied to an Unmanned Aerial Vehicle (UAV) holder is characterized by comprising the following steps of: the cradle head controls the gesture through a plurality of servo motors, and an angle encoder is arranged on the output shaft of each servo motor; Acquiring a measuring range A of an attitude angle of the unmanned aerial vehicle, acquiring an encoder value B of the angle encoder corresponding to the measuring range A, and establishing a conversion relation between the encoder value B and the attitude angle of the unmanned aerial vehicle; In-flight cradle head establishes communication with the unmanned aerial vehicle, obtains the variation of the attitude angle of the unmanned aerial vehicle in real time, converts the variation into the variation of the corresponding encoder value according to the conversion relation, and adjusts the cradle head attitude by the servo motor according to the obtained variation of the encoder value.
2. The IMU-free attitude adjustment method applied to an unmanned aerial vehicle pan-tilt according to claim 1, wherein the pan-tilt controls the pan-tilt attitude by controlling rotations of output shafts in three mutually perpendicular directions by three servo motors.
3. The IMU-free attitude adjustment method applied to a cradle head of an unmanned aerial vehicle according to claim 1, wherein the conversion relation includes a numerical relation and a direction relation, and the encoder adjustment direction is opposite to the unmanned aerial vehicle attitude angle change direction.
4. The IMU-free attitude adjustment method applied to a cradle head of an unmanned aerial vehicle according to claim 1, wherein before flying, both the unmanned aerial vehicle and the cradle head are in a neutral position, the value of the angle encoder is in a neutral position 0, and the attitude angle of the unmanned aerial vehicle is in a neutral position 0 degree.
5. An IMU-free attitude adjustment system applied to an unmanned aerial vehicle (unmanned aerial vehicle) holder, comprising: The cradle head controls the gesture through a plurality of servo motors, and the angle encoder is arranged on the output shaft of each servo motor; The normalization module is connected with the unmanned aerial vehicle control system and the angle encoder and is used for acquiring the measuring range A of the attitude angle of the unmanned aerial vehicle, acquiring the encoder value B of the angle encoder corresponding to the measuring range A and establishing the conversion relation between the encoder value B and the attitude angle of the unmanned aerial vehicle; And the attitude adjusting module is connected with the angle encoder and the normalization module and is used for acquiring the variation of the attitude angle of the unmanned aerial vehicle in flight in real time, converting the variation into the variation corresponding to the encoder value according to the conversion relation, and adjusting the attitude of the cradle head by the servo motor according to the obtained variation of the encoder value.

Description

IMU-free posture adjustment method and system applied to unmanned aerial vehicle holder Technical Field The invention relates to the field of motion control, in particular to an IMU-free posture adjustment method and system applied to an Unmanned Aerial Vehicle (UAV) holder. Background In the existing unmanned aerial vehicle cradle head control technology, an IMU (Inertial Measurement Unit, an inertial measurement unit) is added in a cradle head, namely an electronic stability augmentation device, and the cradle head is subjected to attitude control firstly and then combined with the movement of an unmanned aerial vehicle to perform fusion attitude control. In the prior art, the cradle head independently uses the electronic stability augmentation device IMU, so that spontaneous posture adjustment can be achieved, but the added IMU device increases the cost of the cradle head. The gesture calculation of the IMU needs to occupy large CPU resources, so that the MCU with relatively strong calculation capability is needed for control, and more resource consumption is caused. The movement of the unmanned aerial vehicle holder is the movement which is strongly related to the movement of the unmanned aerial vehicle, so that the performance and the resource waste can be greatly reduced as long as the unmanned aerial vehicle holder can be coupled and synchronized with the movement of the unmanned aerial vehicle, and the real utilization rate of the unmanned aerial vehicle holder by adding an independent IMU is not high. The invention patent ZL 201611245415.0 relates to the field of aircrafts and discloses a tripod head stability augmentation system which is arranged in a tripod head as shown in figure 1 and comprises a mechanical stability augmentation device and an electronic stability augmentation device, wherein the mechanical stability augmentation device and the electronic stability augmentation device are electrically connected with a same group of vibration sensors, the group of vibration sensors are fixed in the tripod head, the mechanical stability augmentation device is used for controlling the tripod head to perform mechanical movement opposite to the detected vibration direction according to output signals of the vibration sensors through an electronic control mechanical structure so as to offset shaking of the tripod head, so as to realize mechanical stability augmentation, the mechanical stability augmentation device outputs shaking residual data after mechanical stability augmentation to the electronic stability augmentation device, and the electronic stability augmentation device is used for eliminating various shaking of an image through image processing of a camera of the tripod head according to the shaking residual data and the output signals of the vibration sensors, so as to realize two-stage stability augmentation. The effect that the picture is very stable is achieved by only clipping the picture of the image by a few tenths of a pixel. The design disadvantages of the above patent systems are: 1. the resources of the aircraft are not reasonably utilized, and the cost of the cradle head part is too high due to the addition of electronic stability augmentation hardware; 2. The CPU needs to control the cradle head and also calculates an electronic stability augmentation device, and the cost is excessive. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides an IMU-free posture adjustment method and system applied to an Unmanned Aerial Vehicle (UAV) holder, the method is suitable for posture control of the UAV holder, the electronic stability augmentation device IMU of the cradle head is reduced, the problem of cradle head posture control can be solved only through interaction with an unmanned aerial vehicle, and the purposes of cost reduction and efficiency augmentation are achieved. In order to achieve the above purpose, the present invention provides the following technical solutions: an IMU-free posture adjustment method applied to an Unmanned Aerial Vehicle (UAV) holder comprises the following steps of: the cradle head controls the gesture through a plurality of servo motors, and an angle encoder is arranged on the output shaft of each servo motor; Acquiring a measuring range A of an attitude angle of the unmanned aerial vehicle, acquiring an encoder value B of the angle encoder corresponding to the measuring range A, and establishing a conversion relation between the encoder value B and the attitude angle of the unmanned aerial vehicle; In-flight cradle head establishes communication with the unmanned aerial vehicle, obtains the variation of the attitude angle of the unmanned aerial vehicle in real time, converts the variation into the variation of the corresponding encoder value according to the conversion relation, and adjusts the cradle head attitude by the servo motor according to the obtained variation of the encoder value. As a further scheme o