A gimbal control method and device for high-altitude spraying of a drone

Abstract

The application discloses a gimbal control method and device for high-altitude spraying of an unmanned aerial vehicle, wherein a nozzle and an attitude sensor are arranged on the gimbal, and the gimbal is controlled to rotate through a three-axis motor; the method comprises the following steps: collecting an Euler angle signal of the nozzle through the attitude sensor; inputting the Euler angle signal into a tracking differentiator for signal tracking and differential processing, and outputting an angle tracking differential signal; detecting a real-time speed of the three-axis motor; observing the real-time speed through a linear extended observer, and outputting a speed observation differential signal and a total disturbance signal; calculating a system error according to the angle tracking differential signal and the speed observation differential signal, and inputting the system error into a linear error compensation controller; calculating a speed target value of the three-axis motor according to the system error and the total disturbance signal through the linear error compensation controller; and controlling a rotating speed of the three-axis motor according to the speed target value; and the method can improve the stability and reliability of high-altitude spraying of the nozzle.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a gimbal control method and device for high-altitude spraying of UAVs. Background Technology

[0002] Traditional high-altitude spraying with live electrical lines relies primarily on human-vehicle collaboration, a method that is not only inefficient but also carries significant safety risks. Especially in areas prone to tree-line conflicts and bird damage, the maintenance and repair of high-fault lines are constrained by various factors, such as the difficulty of accessing live-line vehicles, the challenges of conducting live-line work, and limitations imposed by terrain and space. Furthermore, traditional high-altitude spraying with live electrical lines requires complex safety measures, such as constructing safety protection facilities and establishing warning zones, which increase the complexity and cost of the operation. Therefore, this traditional method of power maintenance is no longer sufficient to meet the demands of modern power systems for efficiency, safety, and environmental friendliness.

[0003] To address the aforementioned issues, drone-based spraying technology has emerged. This technology, through automated and intelligent operation, realizes the entire process of inspection, spraying, and acceptance, significantly shortening the closed-loop cycle of defect handling and substantially improving work efficiency. For example, patent text CN220430506U discloses an adjustable spraying motion device for spraying drones, including an adjustable device support frame and a power supply. The adjustable device support frame includes a spray gun adjustment control mechanism, a telescopic mechanism, and a 2D motion gimbal for the spray gun; the telescopic mechanism includes a telescopic rod and a telescopic rod positioning support rod; the 2D motion gimbal for the spray gun includes a telescopic rod gimbal fixing base, a 2D gimbal mechanism, and a gimbal spray gun fixing sleeve. The power supply is installed inside the power supply box. Support beams are mounted on both sides of the power supply box; the left one is the rear support beam, and the right one is the front support beam. A spray gun adjustment control mechanism is installed on the lower side of the power supply box. This mechanism has front and rear limit blocks for the slider; the front limit block is located on the right, and the rear limit block is located on the left. A left limit switch for slider operation is mounted on the rear limit block, and a right limit switch is mounted on the front limit block. The spray gun position and attitude are automatically adjusted according to the UAV's spatial location.

[0004] During spraying operations, drones are easily affected by wind and body vibration, causing shaking during the spraying process. For spraying small parts such as insulation defects on power poles, shaking can lead to inaccurate spraying positions and low spraying reliability. Summary of the Invention

[0005] This invention provides a gimbal control method and device for high-altitude spraying of drones, which can improve the reliability of high-altitude spraying of drones.

[0006] A gimbal control method for high-altitude spraying of unmanned aerial vehicles, wherein the gimbal is equipped with a nozzle and an attitude sensor, and the rotation of the gimbal is controlled by a three-axis motor;

[0007] The method includes:

[0008] The Euler angle signal of the nozzle is acquired by the attitude sensor;

[0009] The Euler angle signal is input to a tracking differentiator for signal tracking and differentiation processing, and the output angle tracking differential signal is generated.

[0010] The real-time speed of the three-axis motor is detected and input to the linear extended observer;

[0011] The linear extended observer observes the real-time velocity and outputs the velocity observation differential signal and the total disturbance signal;

[0012] The system error is calculated based on the angle tracking differential signal and the velocity observation differential signal, and the system error is input to the linear error compensation controller.

[0013] The linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal;

[0014] The rotational speed of the three-axis motor is controlled according to the target speed value.

[0015] Furthermore, the Euler angle signal of the nozzle includes a nutation angle signal, a precession angle signal, and a spin angle signal;

[0016] The three-axis motor is used to control the roll axis, yaw axis, and pitch axis of the gimbal.

[0017] Furthermore, the angle tracking differential signal includes the differential signal of the Euler angle and the tracking signal;

[0018] The Euler angle signal is input to a tracking differentiator for signal tracking and differentiation processing, and outputs an angle tracking differential signal, including:

[0019] Calculate the fastest control synthesis function based on the input Euler angle signal;

[0020] Based on the differential signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the fastest control synthesis function, the differential signal of the Euler angles at the current moment is calculated.

[0021] The tracking signal of the Euler angles at the current moment is calculated based on the tracking signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the differential signal of the Euler angles output by the tracking differentiator in the previous round.

[0022] Furthermore, the velocity observation differential signal includes a velocity observation signal and a velocity differential signal;

[0023] The linear extended observer observes the real-time velocity and outputs a velocity observation differential signal and a total disturbance signal, including:

[0024] Based on the real-time velocity and the velocity observation signal output by the previous round of linear extended observer, calculate the total output disturbance signal;

[0025] The current speed differential signal is calculated based on the real-time speed, the speed observation signal output by the previous linear extended observer, the speed target value of the three-axis motor obtained from the previous calculation, and the total disturbance signal.

[0026] The current velocity observation signal is calculated based on the real-time velocity, the velocity observation signal output by the previous linear extended observer, and the velocity differential signal output by the previous linear extended observer.

[0027] Further, the system error is calculated based on the angle tracking differential signal and the velocity observation differential signal, including:

[0028] The actual state error is calculated based on the tracking signal of the Euler angle at the current moment and the current velocity observation signal;

[0029] The differential error is calculated based on the differential signal of the Euler angle at the current moment and the differential signal of the current velocity.

[0030] Furthermore, the linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal, including:

[0031] Calculate the speed value of the preceding stage based on the actual state error, differential error, and corresponding gain coefficient;

[0032] The target speed value is obtained by compensating the preceding speed value based on the total disturbance signal and the preset system coefficient.

[0033] Furthermore, the target speed value is the ratio of the difference between the preceding speed value and the total disturbance signal calculated based on the target speed value to a preset system coefficient.

[0034] Furthermore, controlling the rotational speed of the three-axis motor according to the target speed value includes:

[0035] Collect the current information and rotor angle information of the three-axis motor, and perform Clark transformation and Park transformation based on the current information and rotor angle information to obtain the d-axis current and q-axis current in the synchronous rotating coordinate system.

[0036] Based on the rotor angle information, differential processing is performed to obtain the rotor angular velocity;

[0037] The target speed value and the rotor angular velocity are input into the speed regulator for calculation, and the desired current value is output.

[0038] The desired current value, d-axis current, and q-axis current are input to the current regulator to calculate the target d-axis voltage value and the target q-axis voltage value.

[0039] Based on the rotor angle information, inverse Park transform and inverse Clark transform are performed on the d-axis voltage target value and q-axis voltage target value to obtain the three-phase expected voltage values ​​for the three-axis motor;

[0040] SVPWM modulation is performed based on the desired three-phase voltage values ​​to generate a control signal that controls the rotation speed of the three-axis motor.

[0041] A gimbal control device for high-altitude spraying of unmanned aerial vehicles (UAVs) using the above method includes:

[0042] An angle acquisition module is used to acquire the Euler angle signal of the nozzle through the attitude sensor;

[0043] A tracking differentiator is used to perform signal tracking and differentiation processing based on the Euler angle signal, and output an angle tracking differential signal.

[0044] The speed detection module is used to detect the real-time speed of the three-axis motor and input the real-time speed of the three-axis motor to the linear extended observer;

[0045] A linear extended observer is used to observe the real-time velocity and outputs the velocity observation differential signal and the total disturbance signal;

[0046] The error compensation module is used to calculate the system error based on the angle tracking differential signal and the velocity observation differential signal, and input the system error to the linear error compensation controller;

[0047] A linear error compensator is used to calculate and output the target speed value of the three-axis motor based on the system error and the total disturbance signal.

[0048] The motor control module is used to control the rotation speed of the three-axis motor according to the target speed value.

[0049] Furthermore, the Euler angle of the nozzle includes a nutation angle signal, a precession angle signal, and a spin angle signal;

[0050] The three-axis motor is used to control the roll axis, yaw axis, and pitch axis of the gimbal.

[0051] Furthermore, the angle tracking differential signal includes the differential signal of the Euler angle and the tracking signal;

[0052] The tracking differentiator performs signal tracking and differentiation processing based on the Euler angles, and outputs an angle tracking differential signal, including:

[0053] Calculate the fastest control synthesis function based on the input Euler angle signal;

[0054] Based on the differential signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the fastest control synthesis function, the differential signal of the Euler angles at the current moment is calculated.

[0055] The tracking signal of the Euler angles at the current moment is calculated based on the tracking signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the differential signal of the Euler angles output by the tracking differentiator in the previous round.

[0056] Furthermore, the velocity observation differential signal includes a velocity observation signal and a velocity differential signal;

[0057] The linear extended observer observes the real-time velocity and outputs a velocity observation differential signal and a total disturbance signal, including:

[0058] Based on the real-time velocity and the velocity observation signal output by the previous round of linear extended observer, calculate the total output disturbance signal;

[0059] The current speed differential signal is calculated based on the real-time speed, the speed observation signal output by the previous linear extended observer, the speed target value of the three-axis motor obtained from the previous calculation, and the total disturbance signal.

[0060] The current velocity observation signal is calculated based on the real-time velocity, the velocity observation signal output by the previous linear extended observer, and the velocity differential signal output by the previous linear extended observer.

[0061] Furthermore, the error compensation module calculates the system error based on the angle tracking differential signal and the velocity observation differential signal, including:

[0062] The actual state error is calculated based on the tracking signal of the Euler angle at the current moment and the current velocity observation signal;

[0063] The differential error is calculated based on the differential signal of the Euler angle at the current moment and the differential signal of the current velocity.

[0064] Furthermore, the linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal, including:

[0065] Calculate the speed value of the preceding stage based on the actual state error, differential error, and corresponding gain coefficient;

[0066] The target speed value is obtained by compensating the preceding speed value based on the total disturbance signal and the preset system coefficient.

[0067] Furthermore, the target speed value is the ratio of the difference between the preceding speed value and the total disturbance signal calculated based on the target speed value to a preset system coefficient.

[0068] Furthermore, the motor control module controls the rotational speed of the three-axis motor according to the target speed value, including:

[0069] Collect the current information and rotor angle information of the three-axis motor, and perform Clark transformation and Park transformation based on the current information and rotor angle information to obtain the d-axis current and q-axis current in the synchronous rotating coordinate system.

[0070] Based on the rotor angle information, differential processing is performed to obtain the rotor angular velocity;

[0071] The target speed value and the rotor angular velocity are input into the speed regulator for calculation, and the desired current value is output.

[0072] The desired current value, d-axis current, and q-axis current are input to the current regulator to calculate the target d-axis voltage value and the target q-axis voltage value.

[0073] Based on the rotor angle information, inverse Park transform and inverse Clark transform are performed on the d-axis voltage target value and q-axis voltage target value to obtain the three-phase expected voltage values ​​for the three-axis motor;

[0074] SVPWM modulation is performed based on the desired three-phase voltage values ​​to generate a control signal that controls the rotation speed of the three-axis motor.

[0075] An electronic device includes a processor and a storage device, the storage device storing a plurality of instructions, the processor being configured to read the instructions and execute the method described above.

[0076] The gimbal control method and apparatus for high-altitude spraying of unmanned aerial vehicles provided by the present invention have at least the following beneficial effects:

[0077] (1) Collect the Euler angle signal of the nozzle and the real-time speed of the three-axis motor. Track the Euler angle signal through the tracking differentiator, observe the real-time speed through the linear extension observer, calculate and output the target speed value of the three-axis motor through the linear error compensator, and control the three-axis motor based on the target speed value. The coordinated cooperation of the tracking differentiator, the linear extension observer and the linear error compensator can quickly and accurately control and adjust the speed of the three-axis motor based on the Euler angle of the nozzle, thereby quickly adjusting the angle of the gimbal roll axis, yaw axis and pitch axis, which to a certain extent overcomes the nozzle shaking problem caused by flight instability and ensures the accuracy and reliability of nozzle spraying.

[0078] (2) Using a tracking differentiator for Euler angle signal tracking has good noise resistance and can effectively avoid error accumulation and signal oscillation caused by noise.

[0079] (3) A linear extended observer and real-time velocity are used for observation. By observing unknown disturbances and system dynamic characteristics online, the output of the controller is adjusted in real time to achieve the purpose of precise control. Attached Figure Description

[0080] Figure 1 This is a flowchart of one embodiment of the gimbal control method for high-altitude spraying of drones provided by the present invention.

[0081] Figure 2 This is a control block diagram of the gimbal control method for high-altitude spraying of drones provided by the present invention.

[0082] Figure 3 This is a flowchart of one embodiment of the tracking differentiator signal processing in the gimbal control method for high-altitude spraying of unmanned aerial vehicles provided by the present invention.

[0083] Figure 4 This is a flowchart of one embodiment of the linear extended observer signal processing in the gimbal control method for high-altitude spraying of unmanned aerial vehicles provided by the present invention.

[0084] Figure 5 This is a flowchart illustrating an embodiment of the gimbal control method for high-altitude spraying of drones provided by the present invention, which calculates the error.

[0085] Figure 6 This is a flowchart of an embodiment of the linear error compensator signal processing in the gimbal control method for high-altitude spraying of unmanned aerial vehicles provided by the present invention.

[0086] Figure 7 This is a control block diagram of one embodiment of the motor control in the gimbal control method for high-altitude spraying of drones provided by the present invention.

[0087] Figure 8This is a flowchart of one embodiment of the motor control in the gimbal control method for high-altitude spraying of drones provided by the present invention.

[0088] Figure 9 A flowchart of one embodiment of the gimbal control device for high-altitude spraying of drones provided by the present invention. Detailed Implementation

[0089] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0090] refer to Figure 1 In some embodiments, a gimbal control method for high-altitude spraying of unmanned aerial vehicles is provided, wherein the gimbal is equipped with a nozzle and an attitude sensor, and the gimbal is controlled to rotate by a three-axis motor;

[0091] The method includes:

[0092] S1. Acquire the Euler angle signal of the nozzle through the attitude sensor;

[0093] S2. Input the Euler angle signal into the tracking differentiator for signal tracking and differentiation processing, and output the angle tracking differential signal;

[0094] S3. Detect the real-time speed of the three-axis motor and input the real-time speed of the three-axis motor to the linear extended observer;

[0095] S4. The linear extended observer observes the real-time velocity and outputs the velocity observation differential signal and the total disturbance signal;

[0096] S5. Calculate the system error based on the angle tracking differential signal and the velocity observation differential signal, and input the system error to the linear error compensation controller;

[0097] S6. The linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal;

[0098] S7. Control the rotation speed of the three-axis motor according to the target speed value.

[0099] Specifically, in step S1, the Euler angle signal of the nozzle includes the nutation angle signal, the precession angle signal, and the spin angle signal;

[0100] The three-axis motor is used to control the roll axis, yaw axis, and pitch axis of the gimbal.

[0101] In some embodiments, the three-axis motor includes a first motor, a second motor, and a third motor. The first motor is used to control the roll axis of the gimbal, the second motor is used to control the yaw axis of the gimbal, and the third motor is used to control the pitch axis of the gimbal.

[0102] Specifically, the nutation angle is input to the tracking differentiator for signal tracking and differentiation processing, and outputs a nutation angle tracking differential signal. The real-time speed of the first motor is detected and input to the linear extended observer. The linear extended observer calculates and outputs the speed differential signal of the first motor and the total disturbance signal based on the real-time speed of the first motor. It calculates the first system error based on the nutation angle tracking differential signal and the speed observation differential signal of the first motor, and inputs the first system error to the linear error compensation controller. The linear error compensation controller calculates and outputs the target value of the first motor speed based on the first system error and the total disturbance signal.

[0103] The advance angle is input to the tracking differentiator for signal tracking and differentiation processing, and outputs the advance angle tracking differential signal. The real-time speed of the second motor is detected and input to the linear extension observer. The linear extension observer calculates and outputs the speed observation differential signal of the second motor and the total disturbance signal based on the real-time speed of the second motor. The second system error is calculated based on the advance angle tracking differential signal and the speed observation differential signal of the second motor, and the second system error is input to the linear error compensation controller. The linear error compensation controller calculates and outputs the target value of the second motor speed based on the second system error and the total disturbance signal.

[0104] The rotation angle is input to the tracking differentiator for signal tracking and differentiation processing, and outputs the rotation angle tracking differential signal. The real-time speed of the third motor is detected and input to the linear extended observer. The linear extended observer calculates and outputs the speed observation differential signal of the third motor and the total disturbance signal based on the real-time speed of the third motor. The third system error is calculated based on the rotation angle tracking differential signal and the speed observation differential signal of the third motor, and the third system error is input to the linear error compensation controller. The linear error compensation controller calculates and outputs the target speed value of the third motor based on the third system error and the total disturbance signal.

[0105] In an embodiment of the present invention, gimbal control is performed in coordination by a tracking differentiator, a linear extended observer, and a linear error compensation controller. The nutation angle, precession angle, and rotation angle of Euler angles are respectively input to the tracking differentiator, and the control signals output by the calculation control the roll axis, yaw axis, and pitch axis of the gimbal.

[0106] Further, refer to Figure 2 and Figure 3 In step S2, the angle tracking differential signal includes the differential signal of Euler angles and the tracking signal;

[0107] The Euler angle signal is input to a tracking differentiator for signal tracking and differentiation processing, and outputs an angle tracking differential signal, including:

[0108] S21. Calculate the fastest control synthesis function based on the input Euler angle signal;

[0109] S22. Based on the differential signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the fastest control synthesis function, obtain the differential signal of the Euler angles at the current moment.

[0110] S23. Based on the tracking signal of Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the differential signal of Euler angles output by the tracking differentiator in the previous round, calculate the tracking signal of Euler angles at the current moment.

[0111] Specifically, the tracking differentiator (TD) aims to address the impact of drastic changes in the input signal on the control system and provide the controller with accurate information on the rate of signal change. Compared to traditional differentials, the tracking differentiator has better noise immunity, effectively avoiding error accumulation and signal oscillation problems caused by noise. Its expression is shown below:

[0112]

[0113] Where v1(k+1) represents the tracking signal of the Euler angle at the current time, v1(k) represents the tracking signal of the Euler angle obtained in the previous round of calculation, h represents the integration step size, v2(k+1) represents the differential signal of the Euler angle at the current time, v2(k) represents the differential signal of the Euler angle obtained in the previous round of calculation, h0 is the filtering parameter, and f h Here, v(k) represents the current input Euler angle signal, and r is a parameter for adjusting the tracking speed.

[0114] Specifically, in step S21, the fastest control synthesis function is a function of the difference between the tracking signal v1(k) of the Euler angles obtained in the previous round of calculation and the currently input Euler angle signal v(k), and the differential signal v2(k) of the Euler angles obtained in the previous round of calculation. Based on the input Euler angle signal v(k), the fastest control synthesis function f is calculated. h As shown in equation (3).

[0115] In step S22, based on the differential signal v2(k) of the Euler angles obtained in the previous round, the set integration step size h, and the fastest control synthesis function f... h The differential signal v2(k+1) of the Euler angle at the current moment is calculated, as shown in equation (2).

[0116] In step S23, the tracking signal v1(k+1) of the Euler angle at the current time is calculated based on the tracking signal v1(k) of the Euler angle obtained in the previous round, the set integration step size h, and the differential signal v2(k) of the Euler angle obtained in the previous round, as shown in equation (1).

[0117] In some embodiments, in step S2, the Euler angle signal is input to the tracking differentiator for signal tracking and differentiation processing. This involves inputting the nutation angle, precession angle, and rotation angle to the tracking differentiator for signal tracking and differentiation processing, and outputting the corresponding angle tracking differential signal.

[0118] Further, in step S3, the real-time speed of the three-axis motor is detected and input to the linear extended observer. Specifically, the real-time speed of the three-axis motor in the three control directions is detected and input to the linear extended observer respectively.

[0119] The Linear Extended Observer (LESO) is a special form of the Extended State Observer (ESO) used for state estimation and disturbance compensation in dynamic systems. The core objective of LESO is to compensate for the nonlinearity and uncertainty of the system by observing its state and unknown disturbances in real time, thereby improving the system's robustness and control performance. LESO is primarily used to actively suppress the effects of external disturbances and uncertainties on the system, especially in complex systems that are difficult to model. It achieves precise control by observing unknown disturbances and system dynamic characteristics online and adjusting the controller output in real time.

[0120] refer to Figure 2 and Figure 4 In step S4, the velocity observation differential signal includes a velocity observation signal and a velocity differential signal;

[0121] The linear extended observer observes the real-time velocity and outputs a velocity observation differential signal and a total disturbance signal, including:

[0122] S41. Calculate the total disturbance signal based on the real-time velocity and the velocity observation signal output by the previous linear extended observer.

[0123] S42. Calculate the current speed differential signal based on the real-time speed, the speed observation signal output by the linear extended observer in the previous round, the speed target value of the three-axis motor obtained in the previous round, and the total disturbance signal;

[0124] S43. Obtain the current speed observation signal based on the real-time speed, the speed observation signal output by the previous linear extended observer, and the speed differential signal output by the previous linear extended observer.

[0125] Specifically, the mathematical expression for the linear extended observer is as follows:

[0126]

[0127] in, This represents the velocity observation signal output by the previous linearly extended observer. This represents the velocity differential signal output by the previous linear extended observer. This represents the total output perturbation from the previous round of linearly extended observer output. Indicates the current speed observation signal. This represents the differential signal of the current velocity. The current output is the total disturbance signal. β1, β2, and β3 are the speed observation gain coefficient, the differential observation gain coefficient, and the total disturbance observation gain coefficient, respectively. The tracking effect on the state variables can be controlled by adjusting the three gain coefficients. u' is the target speed value of the three-axis motor obtained from the previous calculation, and b0 is the system coefficient.

[0128] Specifically, in step S41, the velocity is determined based on the real-time velocity y and the velocity observation signal output by the previous linear extended observer. Calculate the difference, then multiply it by the total disturbance observation gain coefficient β3 to obtain the total disturbance signal. As shown in equation (6).

[0129] In step S42, based on the real-time velocity y and the velocity observation signal output by the previous linear extended observer... Total disturbance signal Using the system coefficient b0, the target speed value u' of the three-axis motor obtained from the previous calculation, and the differential observation gain coefficient β2, the current speed differential signal is calculated. As shown in equation (5).

[0130] In step S43, based on the real-time velocity y and the velocity observation signal output by the previous linear extended observer... This represents the velocity differential signal output by the previous linear extended observer. And the velocity observation gain coefficient β1, to calculate the current velocity observation signal. As shown in equation (4).

[0131] Specifically, in step S4, the real-time speed signal processing involves processing the real-time speeds in the three control directions of the three-axis motor.

[0132] Further, refer to Figure 5 In step S5, the system error is calculated based on the angle tracking differential signal and the velocity observation differential signal, including:

[0133] S51. Calculate the actual state error based on the tracking signal of the Euler angle at the current moment and the velocity observation signal;

[0134] S52. Calculate the differential error based on the differential signal of the Euler angle at the current moment and the differential signal of the velocity.

[0135] Specifically, in step S51, the actual state error is calculated using the following formula:

[0136]

[0137] Where e1 represents the actual state error, and v1(k+1) represents the tracking signal of the Euler angles at the current moment. This indicates the current velocity observation signal.

[0138] Furthermore, in step S52, the differential error is calculated using the following formula:

[0139]

[0140] Where e2 represents the differential error, and v2(k+1) represents the differential signal of the Euler angle at the current moment. This represents the differential signal of the current velocity.

[0141] In step S5, the system error is input to the linear error compensation controller. The linear error compensation controller (LESF) is a controller based on the feedback control principle, mainly used for error compensation and adjustment in dynamic systems. Its core idea is to measure the system error (i.e., the deviation between the actual system output and the desired output) and use this error value to feed back to the controller for adjustment, thereby achieving the purpose of precise control.

[0142] Further, refer to Figure 6 In step S6, the linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal, including:

[0143] S61. Calculate the speed value of the preceding stage based on the actual state error, differential error, and corresponding gain coefficient;

[0144] S62. The preceding speed value is compensated based on the total disturbance signal and the preset system coefficient to obtain the target speed value.

[0145] Specifically, the current velocity observation signal output by the linearly extended observer. Current velocity differential signal The actual state error e1 and the differential error e2 are calculated using the tracking signal v1(k+1) of the Euler angle at the current time output by the tracking differentiator and the differential signal v2(k+1) of the Euler angle at the current time. The actual state error e1 and the differential error e2 are input to the linear error compensator to calculate and output the preceding velocity value u0. Based on the total output disturbance of the linear extended observer and the preceding velocity value u0, the velocity target value u is calculated.

[0146] Specifically, in step S61, the preceding speed value is calculated according to the following formula:

[0147] u0 = b1·e1 + b2·e2; (9)

[0148] Where u0 represents the velocity value of the preceding stage, e1 represents the actual state error, e2 represents the differential error, and b1 and b2 are the gain coefficients.

[0149] In step S62, the target velocity value is calculated using the following formula:

[0150]

[0151] Where u is the target speed value, and u0 represents the previous speed value. b0 represents the total output disturbance, and b0 represents the system coefficient.

[0152] Specifically, refer to Figure 2 The acquired Euler angle signal v is input to the tracking differentiator TD, which calculates and outputs the differential signal v of the Euler angle at the current moment. 2( The tracking signal v1(k+1) of k+1 and the Euler angle at the current moment; the real-time speed y of the three-axis motor are input to the linear extended observer LESO, which calculates and outputs the current speed observation signal. Current velocity differential signal Total disturbance signal Then, based on the current speed observation signal Current velocity differential signal The differential signal v of the Euler angle at the current moment 2( The actual state error e1 and the differential error e2 are calculated using the tracking signal v1(k+1) and the Euler angle tracking signal v1(k+1) at the current time. These errors are then input to the linear error compensation controller LESF to calculate the preceding velocity value u0. Based on the preceding velocity value u0 and the total disturbance signal... The target velocity value u is calculated.

[0153] Specifically, refer to Figure 7 and Figure 8 In step S7, controlling the rotational speed of the three-axis motor according to the target speed value includes:

[0154] S71. Collect the current information and rotor angle information of the three-axis motor, and perform Clark transformation and Park transformation based on the current information and rotor angle information to obtain the d-axis current and q-axis current in the synchronous rotating coordinate system.

[0155] S72. Based on the rotor angle information, perform differential processing to obtain the rotor angular velocity;

[0156] S73. Input the target speed value and the rotor angular velocity into the speed regulator for calculation, and output the desired current value;

[0157] S74. Input the desired current value, d-axis current and q-axis current to the current regulator, and calculate the target d-axis voltage value and the target q-axis voltage value.

[0158] S75. Based on the rotor angle information, perform inverse Park transform and inverse Clark transform on the target values ​​of the d-axis voltage and the target values ​​of the q-axis voltage to obtain the three-phase expected voltage values ​​of the three-axis motor.

[0159] S76. SVPWM modulation is performed based on the three-phase desired voltage values ​​to generate a control signal to control the rotation speed of the three-axis motor.

[0160] refer to Figure 7 In this embodiment, the three-axis motor is controlled based on the FOC motor control algorithm, including a speed control loop mainly composed of a speed regulator and a current control loop mainly composed of a current regulator. Specifically, the rotor angle θ and current I of the three-axis motor are acquired through an encoder. abc After Clark and Park transformations, the d-axis current Id and q-axis current Iq in the synchronous rotating coordinate system are obtained. Simultaneously, the rotor angle θ is differentiated to obtain the rotor angular velocity. The obtained target speed value u and rotor angular velocity are input to the speed regulator for calculation, outputting the expected current value. This expected current value is the expected current value for the q-axis, and the expected current value for the d-axis is 0. The obtained expected current value for the q-axis, the d-axis current Id, and the q-axis current Iq are input to the current regulator to calculate the target voltage values ​​Vd and Vq for the d-axis and q-axis. Based on the rotor angle θ, the inverse Park and inverse Clark transformations are performed on the target voltage values ​​Vd and Vq for the d-axis and q-axis, respectively, to obtain the three-phase expected voltage values ​​Va, Vb, and Vc for the three-axis motor. Finally, these are updated to the PWM output of each phase via the SVM mechanism, and finally applied to the motor by the three-phase inverter bridge.

[0161] refer to Figure 9 In some embodiments, a gimbal control device for high-altitude spraying of unmanned aerial vehicles (UAVs) using the above-described method is provided, comprising:

[0162] Angle acquisition module 201 is used to acquire the Euler angle signal of the nozzle through the attitude sensor;

[0163] The tracking differentiator 202 is used to perform signal tracking and differentiation processing based on the Euler angle signal, and output an angle tracking differential signal.

[0164] The speed detection module 203 is used to detect the real-time speed of the three-axis motor and input the real-time speed of the three-axis motor to the linear extended observer;

[0165] Linear extended observer 204 is used to make observations based on the real-time velocity and output a velocity observation differential signal and a total disturbance signal;

[0166] Error compensation module 205 is used to calculate the system error based on the angle tracking differential signal and the velocity observation differential signal, and input the system error to the linear error compensation controller;

[0167] The linear error compensator 206 is used to calculate and output the target speed value of the three-axis motor based on the system error and the total disturbance signal;

[0168] The motor control module 207 is used to control the rotation speed of the three-axis motor according to the target speed value.

[0169] Furthermore, the Euler angle of the nozzle includes a nutation angle signal, a precession angle signal, and a spin angle signal;

[0170] The three-axis motor is used to control the roll axis, yaw axis, and pitch axis of the gimbal.

[0171] Furthermore, the angle tracking differential signal includes the differential signal of the Euler angle and the tracking signal;

[0172] The tracking differentiator 202 performs signal tracking and differentiation processing based on the Euler angles, and outputs an angle tracking differential signal, including:

[0173] Calculate the fastest control synthesis function based on the input Euler angle signal;

[0174] Based on the differential signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the fastest control synthesis function, the differential signal of the Euler angles at the current moment is calculated.

[0175] The tracking signal of the Euler angles at the current moment is calculated based on the tracking signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the differential signal of the Euler angles output by the tracking differentiator in the previous round.

[0176] Furthermore, the velocity observation differential signal includes a velocity observation signal and a velocity differential signal;

[0177] The linear extended observer 204 observes the real-time velocity and outputs a velocity observation differential signal and a total disturbance signal, including:

[0178] Based on the real-time velocity and the velocity observation signal output by the previous round of linear extended observer, calculate the total output disturbance signal;

[0179] The current speed differential signal is calculated based on the real-time speed, the speed observation signal output by the previous linear extended observer, the speed target value of the three-axis motor obtained from the previous calculation, and the total disturbance signal.

[0180] The current velocity observation signal is calculated based on the real-time velocity, the velocity observation signal output by the previous linear extended observer, and the velocity differential signal output by the previous linear extended observer.

[0181] Further, the error compensation module 205 calculates the system error based on the angle tracking differential signal and the velocity observation differential signal, including:

[0182] The actual state error is calculated based on the tracking signal of the Euler angle at the current moment and the current velocity observation signal;

[0183] The differential error is calculated based on the differential signal of the Euler angle at the current moment and the differential signal of the current velocity.

[0184] Further, the linear error compensator 206 calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal, including:

[0185] Calculate the speed value of the preceding stage based on the actual state error, differential error, and corresponding gain coefficient;

[0186] The target speed value is obtained by compensating the preceding speed value based on the total disturbance signal and the preset system coefficient.

[0187] Furthermore, the target speed value is the ratio of the difference between the preceding speed value and the total disturbance signal calculated based on the target speed value to a preset system coefficient.

[0188] Furthermore, the motor control module 207 controls the rotational speed of the three-axis motor according to the target speed value, including:

[0189] Collect the current information and rotor angle information of the three-axis motor, and perform Clark transformation and Park transformation based on the current information and rotor angle information to obtain the d-axis current and q-axis current in the synchronous rotating coordinate system.

[0190] Based on the rotor angle information, differential processing is performed to obtain the rotor angular velocity;

[0191] The target speed value and the rotor angular velocity are input into the speed regulator for calculation, and the desired current value is output.

[0192] The desired current value, d-axis current, and q-axis current are input to the current regulator to calculate the target d-axis voltage value and the target q-axis voltage value.

[0193] Based on the rotor angle information, inverse Park transform and inverse Clark transform are performed on the d-axis voltage target value and q-axis voltage target value to obtain the three-phase expected voltage values ​​for the three-axis motor;

[0194] SVPWM modulation is performed based on the desired three-phase voltage values ​​to generate a control signal that controls the rotation speed of the three-axis motor.

[0195] In some embodiments, an electronic device is also provided, including a processor and a storage device, the storage device storing a plurality of instructions, the processor being configured to read the instructions and execute the methods described above.

[0196] The gimbal control method and apparatus for high-altitude spraying of unmanned aerial vehicles provided in the above embodiments have at least the following beneficial effects:

[0197] (1) Collect the Euler angle signal of the nozzle and the real-time speed of the three-axis motor. Track the Euler angle signal through the tracking differentiator, observe the real-time speed through the linear extension observer, calculate and output the target speed value of the three-axis motor through the linear error compensator, and control the three-axis motor based on the target speed value. The coordinated cooperation of the tracking differentiator, the linear extension observer and the linear error compensator can quickly and accurately control and adjust the speed of the three-axis motor based on the Euler angle of the nozzle, thereby quickly adjusting the angle of the gimbal roll axis, yaw axis and pitch axis, which to a certain extent overcomes the nozzle shaking problem caused by flight instability and ensures the accuracy and reliability of nozzle spraying.

[0198] (2) Using a tracking differentiator for Euler angle signal tracking has good noise resistance and can effectively avoid error accumulation and signal oscillation caused by noise.

[0199] (3) A linear extended observer and real-time velocity are used for observation. By observing unknown disturbances and system dynamic characteristics online, the output of the controller is adjusted in real time to achieve the purpose of precise control.

[0200] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A gimbal control method for high-altitude spraying of unmanned aerial vehicles (UAVs), characterized in that, The gimbal is equipped with a nozzle and an attitude sensor, and the gimbal is controlled to rotate by a three-axis motor; the method includes: The Euler angle signal of the nozzle is acquired by the attitude sensor; The Euler angle signal is input to a tracking differentiator for signal tracking and differentiation processing, and the output angle tracking differential signal is generated. The real-time speed of the three-axis motor is detected and input to the linear extended observer; The linear extended observer observes the real-time speed and outputs a speed observation differential signal and a total disturbance signal: Based on the real-time speed and the speed observation signal output by the linear extended observer in the previous round, the total disturbance signal is calculated and output; based on the real-time speed, the speed observation signal output by the linear extended observer in the previous round, the target speed value of the three-axis motor calculated in the previous round, and the total disturbance signal, the current speed differential signal is calculated; based on the real-time speed, the speed observation signal output by the linear extended observer in the previous round, and the speed differential signal output by the linear extended observer in the previous round, the current speed observation signal is obtained; the speed observation differential signal includes both the speed observation signal and the speed differential signal. The system error is calculated based on the angle tracking differential signal and the velocity observation differential signal, and the system error is input to the linear error compensation controller; the system error includes actual state error and differential error; The linear error compensator calculates and outputs the target speed value of the three-axis motor based on the system error and the total disturbance signal; it calculates the preceding speed value based on the actual state error, differential error and corresponding gain coefficient; and it compensates the preceding speed value based on the total disturbance signal and preset system coefficients to obtain the target speed value. The rotational speed of the three-axis motor is controlled according to the target speed value.

2. The method according to claim 1, characterized in that, The Euler angle signal of the nozzle includes the nutation angle signal, the precession angle signal, and the spin angle signal; The three-axis motor is used to control the roll axis, yaw axis, and pitch axis of the gimbal.

3. The method according to claim 1, characterized in that, The angle tracking differential signal includes the differential signal of Euler angles and the tracking signal; The Euler angle signal is input to a tracking differentiator for signal tracking and differentiation processing, and outputs an angle tracking differential signal, including: Calculate the fastest control synthesis function based on the input Euler angle signal; Based on the differential signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the fastest control synthesis function, the differential signal of the Euler angles at the current moment is calculated. The tracking signal of the Euler angles at the current moment is calculated based on the tracking signal of the Euler angles output by the tracking differentiator in the previous round, the preset integration step size, and the differential signal of the Euler angles output by the tracking differentiator in the previous round.

4. The method according to claim 1, characterized in that, The system error is calculated based on the angle tracking differential signal and the velocity observation differential signal, including: The actual state error is calculated based on the tracking signal of the Euler angle at the current moment and the current velocity observation signal; The differential error is calculated based on the differential signal of the Euler angle at the current moment and the differential signal of the current velocity.

5. The method according to claim 1, characterized in that, The target speed value is the ratio of the difference between the preceding speed value and the total disturbance signal calculated to a preset system coefficient.

6. The method according to claim 1, characterized in that, Controlling the rotational speed of the three-axis motor according to the target speed value includes: Collect the current information and rotor angle information of the three-axis motor, and perform Clark transformation and Park transformation based on the current information and rotor angle information to obtain the d-axis current and q-axis current in the synchronous rotating coordinate system. Based on the rotor angle information, differential processing is performed to obtain the rotor angular velocity; The target speed value and the rotor angular velocity are input into the speed regulator for calculation, and the desired current value is output. The desired current value, d-axis current, and q-axis current are input to the current regulator to calculate the target d-axis voltage value and the target q-axis voltage value. Based on the rotor angle information, inverse Park transform and inverse Clark transform are performed on the d-axis voltage target value and q-axis voltage target value to obtain the three-phase expected voltage values ​​for the three-axis motor; SVPWM modulation is performed based on the desired three-phase voltage values ​​to generate a control signal that controls the rotation speed of the three-axis motor.

7. A gimbal control device for high-altitude spraying of unmanned aerial vehicles (UAVs) using the method described in any one of claims 1-6, characterized in that, include: An angle acquisition module is used to acquire the Euler angle signal of the nozzle through the attitude sensor; A tracking differentiator is used to perform signal tracking and differentiation processing based on the Euler angle signal, and output an angle tracking differential signal. The speed detection module is used to detect the real-time speed of the three-axis motor and input the real-time speed of the three-axis motor to the linear extended observer; A linear extended observer is used to observe the real-time velocity and outputs the velocity observation differential signal and the total disturbance signal; The error compensation module is used to calculate the system error based on the angle tracking differential signal and the velocity observation differential signal, and input the system error to the linear error compensation controller; A linear error compensator is used to calculate and output the target speed value of the three-axis motor based on the system error and the total disturbance signal. The motor control module is used to control the rotation speed of the three-axis motor according to the target speed value.

8. An electronic device, characterized in that, The method includes a processor and a storage device, the storage device storing a plurality of instructions, and the processor being configured to read the instructions and execute the method as described in any one of claims 1-6.

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