WO2022016562A1

WO2022016562A1 - Vision-based crop protection unmanned aerial vehicle obstacle-avoidance system and obstacle avoidance method thereof

Info

Publication number: WO2022016562A1
Application number: PCT/CN2020/104940
Authority: WO
Inventors: 张正强; 段纳; 苗珍; 孟国华
Original assignee: 南京科沃信息技术有限公司
Priority date: 2020-07-22
Filing date: 2020-07-27
Publication date: 2022-01-27
Also published as: CN111781952A

Abstract

Provided are a vision-based crop protection unmanned aerial vehicle obstacle-avoidance system and obstacle avoidance method thereof, the obstacle avoidance system comprising: a power supply module, a control module, and a sensor measurement module; the power supply module transmits an adjusted output power to the control module and the sensor measurement module so as to provide a power source for the system module, and the frequency of a crystal oscillator is used to stabilize a frequency signal; the control module receives a detection signal fed back by the sensor measurement module to control an obtained detection signal, thus driving the operation of the subsequent module; by means of an ultrasonic ranging method, the sensor measurement module determines and estimates, according to the speed of sound waves and the time interval of ultrasonic transmission and reception, an obstacle and the distance between the obstacle and the unmanned aerial vehicle during its flight, and thus makes an accurate determination, and automatically adjusts the flight trajectory to complete a specified flight task.

Description

A vision-based plant protection UAV obstacle avoidance system and its obstacle avoidance method

technical field

The invention relates to the technical field of UAV obstacle avoidance, in particular to a vision-based plant protection UAV obstacle avoidance system and an obstacle avoidance method.

Background technique

With the development of UAV technology, UAVs are widely used in various fields of military and civilian use. Autonomous flight control and obstacle avoidance are the prerequisites to ensure the safe flight of UAVs. Therefore, automatic obstacle avoidance has become the automation of UAVs. Or the key to intelligence, and the so-called "automatic obstacle avoidance" of UAVs means that when UAVs encounter obstacles in the process of automatic flight, they will automatically identify through online measurement, effectively avoid obstacles, and achieve safety. flying system.

The obstacle avoidance acquisition system of the UAV needs to accurately collect the detection sensor data from the UAV, and then through data processing, output attitude angle, yaw angle, altitude, air pressure, position and speed and other information, and the flight control system based on The received information controls the operation of other modules, so that the UAV can fly according to the expected effect, and then detects the accuracy value of the output information of the sensor system, which indirectly affects the quality of the flight, and then fails to achieve the expected flight effect. The control chip of the machine is easily disturbed by external noise and other factors, resulting in low accuracy of the collected data.

SUMMARY OF THE INVENTION

Purpose of the invention: to provide a vision-based plant protection UAV obstacle avoidance system to solve the above problems.

Technical solution: a vision-based plant protection UAV obstacle avoidance system, including:

A power supply module for transmitting the adjusted output power to the control module and the sensor measurement module, thereby providing a power source for the UAV obstacle avoidance system module;

A control module for receiving the detection signal fed back by the sensor measurement module, so as to control the acquired detection signal, and then convey different control instructions;

A sensor measurement module for judging and estimating the obstacles and the distances between the obstacles and the obstacles during the flight of the UAV according to the speed of the ultrasonic waves and the time interval of ultrasonic transmission and reception through the ultrasonic ranging method.

According to one aspect of the present invention, the power supply module includes a power module and a clock reset module, wherein the power module includes a capacitor C2, a capacitor C1, a power supply U1, a capacitor C4, a capacitor C3, and a capacitor C5, wherein the capacitor C2 One end is respectively connected with one end of the capacitor C1, the input power supply 12V, the pin 1 and pin 3 of the power supply U1; the other end of the capacitor C2 is respectively connected with the other end of the capacitor C1 and the U1 pin 2 of the power supply; the power supply U1 leads The pin 5 is respectively connected with one end of the capacitor C3 and the positive terminal of the capacitor C5; the other end of the capacitor C3 is respectively connected with the negative terminal of the capacitor C5 and the ground wire GND; the pin 4 of the power supply device U1 is connected with the negative terminal of the capacitor C4; The positive terminal of C4 is connected to the ground wire GND.

According to an aspect of the present invention, the clock reset module includes a button S1, a capacitor C6, a resistor R1, a transistor Q1, a resistor R2, a resistor R3, and a capacitor C7, wherein one end of the button S1 is respectively connected to one end of the resistor R1 and the positive end of the capacitor C6. Connection; the other end of the button S1 is respectively connected with the negative terminal of the capacitor C6, one end of the resistor R3, the negative terminal of the capacitor C7, and the ground wire GND; the other end of the resistor R1 is connected with the base terminal of the transistor Q1; the emitter terminal of the transistor Q1 is respectively connected with One end of the capacitor C2, one end of the capacitor C1, the input power supply 12V, the pin 1 and pin 3 of the power supply U1 are connected; the collector end of the transistor Q1 is connected with one end of the resistor R2; the other end of the resistor R2 is respectively connected with the other end of the resistor R3, The positive terminal of capacitor C7 is connected.

According to one aspect of the present invention, the control module includes a control unit, an ultrasonic receiving unit, and an alarm module, wherein the control unit includes a controller U2, and the pin 60 of the controller U2 is respectively connected to the other end of the resistor R2 and the other end of the resistor R3. One end, the positive terminal of the capacitor C7 is connected; the pin 5 of the controller U2 and the pin 5 of the power supply U1 are respectively connected to one end of the capacitor C3 and the positive terminal of the capacitor C5; the pin 7 of the controller U2 is respectively connected to one end of the button S1, One end of the resistor R1 and the positive end of the capacitor C6 are connected;

According to an aspect of the present invention, the ultrasonic receiving unit includes a resistor R9, a capacitor C19, a resistor R10, a resistor R8, a capacitor C18, and a receiver L1, wherein one end of the resistor R9 is connected to the controller U2 pin 62; the resistor The other end of R9 is connected to one end of capacitor C19, one end of resistor R10 and one end of resistor R8 respectively; the other end of capacitor C19 is connected to ground GND; the other end of resistor R10 is connected to pin 581 of controller U2; the other end of resistor R8 One end is connected to one end of the capacitor C18; the other end of the capacitor C18 is connected to one end of the receiver L1; the other end of the receiver L1 is connected to the ground wire GND;

According to one aspect of the present invention, the alarm module includes a resistor R7, a transistor Q5, and an alarm LS2, wherein one end of the resistor R7 is connected to the pin 50 of the controller U2; the other end of the resistor R7 is connected to the base terminal of the transistor Q5; The collector terminal of the transistor Q5 is connected to one end of the alarm LS1; the other end of the alarm LS1 is connected to the input power +12V; the emitter terminal of the transistor Q5 is connected to the ground wire GND.

According to one aspect of the present invention, the sensor measurement module includes an operation processing module, a driving module, an A/D conversion module, and an ultrasonic transmitting unit, wherein the operation processing module includes an inductor L1, a capacitor C9, an inductor L2, a diode D2, a diode D1, inductor L3, capacitor C8, and processor U3, wherein one end of the inductor L1 is respectively connected to one end of the capacitor C9, one end of the inductor L2, and the ground wire GND; the other end of the inductor L1 is connected to the pin 9 of the processor U3; the The other end of the capacitor C9 is connected to the processor U3 pin 10; the other end of the inductance L2 is connected to the processor U3 pin 11; the

processor U3 pins

23 and 18 are both connected to the ground wire GND; the processor U3 The pin 20 is connected to the positive terminal of the capacitor C8; the negative terminal of the capacitor C8 is connected to the ground wire GND; the pin 1 of the processor U3 is connected to one end of the inductor L3; the other end of the inductor L3 is connected to the ground wire GND; the The processor U3 pin 4 is respectively connected with the controller U2 pin 7, one end of the button S1, one end of the resistor R1 and the positive end of the capacitor C6; the processor U3 pin 8 is connected with the negative end of the diode D2; the positive end of the diode D2 is connected They are respectively connected to the positive terminal of the diode D1, the pin 5 of the controller U2, and the pin 5 of the power supply U1 to one end of the capacitor C3 and the positive terminal of the capacitor C5, respectively.

According to an aspect of the present invention, the driving module includes a driver U4, a capacitor C10, a diode D5, a capacitor C12, a capacitor C13, and a capacitor C11, wherein the pin 16 of the driver U4 is connected to the pin 42 of the controller U2; the driver U4 pin 13 is respectively connected to one end of capacitor C12, the positive end of diode D5, the negative end of diode D1, the pin 2 and pin 4 of driver U4, and one end of capacitor C10; the other end of the capacitor C10 is connected to the ground wire GND; the capacitor The other end of C12 is respectively connected to one end of capacitor C13, the pin 11 and pin 9 of the driver U4, and the ground wire GND; one end of the capacitor C11 is connected to the pin 12 of the driver U4; the other end of the capacitor C11 is connected to the pin 8 of the starter U4 connect.

According to one aspect of the present invention, the A/D conversion module includes a capacitor C17, a converter U5, an inductor L4, a diode D6, a resistor R6, an inductor L5, a capacitor C15, and a capacitor C16, wherein the converter U5 pin 6 and Pin 3 is respectively connected with one end of capacitor C17, one end of inductor L4, and pin 24 of processor U3; described converter U5 pin 2 is respectively connected with the other end of inductor L4 and the positive end of diode D6; described converter U5 pin 5 Connect to one end of resistor R6, one end of inductor L5 and one end of capacitor C15 respectively; the pin 4 of the converter U5 is respectively connected to the other end of capacitor C17, the other end of resistor R6, one end of capacitor C16, and the ground wire GND; the other end of capacitor C16 Connect to the other end of capacitor C15, the other end of inductor L5, pin 55 of controller U2, and the negative end of diode D6.

According to an aspect of the present invention, the ultrasonic emitting unit includes a transistor Q4, a diode D3, a resistor R5, a diode D4, a resistor R5, a transistor Q3, a capacitor C14, a transistor Q2, a resistor R4, and a transmitter L2, wherein the transistor Q4 collects The electrode terminal is connected to the processor U3 pin 23; the base terminal of the transistor Q4 is connected to the negative terminal of the diode D3; the emitter terminal of the transistor Q4 is respectively connected to the positive terminal of the diode D4, the emitter terminal of the transistor Q3, the emitter terminal of the transistor Q2, and the emitter L2 One end is connected; the positive end of the diode D3 is respectively connected with one end of the resistor R5, the collector end of the transistor Q3, the negative end of the diode D4, one end of the capacitor C14, one end of the resistor R4, the collector end of the transistor Q2, and the negative end of the diode D5; the resistor R5 The other end is respectively connected with the base end of the transistor Q3 and the other end of the capacitor C14; the other end of the resistor R4 is respectively connected with the base end of the transistor Q2 and the other end of the transmitter L2.

According to an aspect of the present invention, the capacitor C4, the capacitor C5, the capacitor C6, the capacitor C7, and the capacitor C8 are electrolytic capacitors; the diode D1, the diode D2, the diode D5 The models are all Zener diodes; the transistor Q1 model is PNP; the transistor Q2, the transistor Q3, the transistor Q4, and the transistor Q5 are all NPN models; the power supply U1 model is MIC5219; the The model of the processor U3 is MPU6050; the model of the controller U2 is STM32; the model of the driver U4 is HMC5883L.

According to one aspect of the present invention, a vision-based obstacle avoidance method for a plant protection UAV obstacle avoidance system is characterized by the following steps:

Step 1. The operation processing module first measures its own attitude information through the processor U3, and then converts the measured three-axis angular velocity and acceleration attitude information into digital signals through the A/D conversion module, and then transmits the digital signals to the control module for processing. deal with;

Step 2. The drive module controls the heading and orientation of the UAV through the change of the ultrasonic ranging sensor, and the driver U4 uses the anisotropic magnetoresistance technology to measure the direction and size of the earth's magnetic field, and the driver U4 pin is connected to the capacitor C11, The function of the capacitor C11 is to filter, thereby improving the response of the driving operation. The capacitor C13 is used as a storage device to provide the driver U4 with a startup power supply, thereby reducing the voltage shock caused by the instantaneous startup.

According to an aspect of the present invention, a vision-based obstacle avoidance method for a plant protection UAV obstacle avoidance system is characterized in that, the

steps

1 and 2 further obtain, the flight attitude angle and the Kalman filter algorithm;

Step 1-1. The flight attitude angle includes roll angle, pitch angle and yaw angle, and the roll angle is the angle between the longitudinal symmetry plane of the body and the longitudinal vertical plane.

Indicates that the pitch angle is the angle between the longitudinal axis of the body and the longitudinal horizontal axis, expressed by θ, and the yaw angle is the angle between the projection of the longitudinal axis of the body on the horizontal plane xoy and the prime meridian in the geographic coordinate system, denoted by ω Therefore, the conversion from the earth coordinate system to the body coordinate system can be realized by three rotations, and the conversion formula is as follows:

Steps 1-2, of which

The attitude matrix is represented as follows:

The flight attitude angle is calculated by the quaternion method, and Q is used to represent the attitude quaternion, where Q=q ₀ + q ₁ i+q ₂ j+q ₃ k, q ₀ is true, q ₁ , q ₂ , q ₃ are imaginary numbers and ‖Q‖=1, and then the above method can be obtained:

Steps 1-3, and then according to the substitution of the above two sets of equations, the relationship between the flight attitude angle and the quaternion can be obtained, and the equation is as follows:

Steps 1-4, and then the differential equation of the attitude quaternion Q is obtained as follows:

Where Q ₀ is a predetermined initial _{_{quaternion, ω x, ω y, ω}} z are x, y, z-axis output angular velocity, and thus can obtain the current quaternion Q _i in accordance with step 1-4, the step of substituting Q _i 1-3 can then obtain the flight attitude angle information at the current moment;

Step 2-1. According to the Kalman filter algorithm, set the current sampling time as k, the last moment as k-1, and the optimal state as

Then according to the Kalman filter algorithm, the following steps are obtained:

Step 2-2, according to

Predict the current state of the obstacle avoidance system, and the predicted value is recorded.

Which leads to the following way:

Wherein A represents a state transition matrix matrix, u _k represents the current time input, the system matrix B denotes the control matrix avoidance,

It consists of two parts, one part is the product between the optimal state at the previous moment and matrix A, and the other part is the product between the input quantity at the current moment and matrix B;

Step 2-3, using the covariance matrix equation, and setting the current state matrix as P _k , the following methods can be obtained:

P _k =AP _k-1 A ^T +Q

where P _k-1 is the optimal solution estimated by the covariance matrix at the previous moment, and Q is the inherent noise matrix of the prediction model;

Step 2-3, set the current observation value as z _k , the current observation matrix as H, and the covariance matrix of the observation noise as R, the following methods can be obtained:

Thus, the predicted value and the observed value are fused to obtain the optimal estimated value of the current state.

The way:

in

Represents the residual between the actual observed value and the predicted value, K is called the Kalman coefficient matrix, and K is expressed as:

K=P _k H ^T /[HP _k H ^T +R]

Among them, the value of K directly affects the proportion of the observed value and the predicted value. The larger the K is, the larger the weighted coefficient of the observed value is, and vice versa; the larger the predicted value;

In order to ensure the recursive operation of the algorithm, it is necessary to update the current optimal estimated value in real time.

The expression of the covariance matrix P′ _k is as follows:

P _k ′=(I-KH)P _k

where I is the identity matrix.

Beneficial effects: The present invention designs a vision-based plant protection UAV obstacle avoidance system and its obstacle avoidance method, which utilizes the processor U3 for the ultrasonic transmitting unit and the driver U4 for acceleration and angular velocity acquisition, and the control unit can be combined with the receiving processor U3. It transmits information with the driver U4, so as to obtain acceleration, angular velocity and azimuth attitude information and perform data fusion processing. In addition, the control chip is easily interfered by external noise and other factors, resulting in low accuracy of the collected data, and then the output The attitude angle of the UAV is converted into a quaternion, and then the Kalman filter algorithm is used to statically correct the data collected by the control. Finally, after filtering and fusion, the attitude angle can reach the operating accuracy. The UAV autonomous obstacle avoidance system has a simple structure and can fly out of control. The risk is greatly reduced, and the flight attitude angle and Kalman filter algorithm are used to reduce the load of the embedded obstacle avoidance system, which enhances the maneuverability and execution of the UAV, and enables the UAV to better avoid obstacles in advance. , adjust the flight direction independently.

Description of drawings

Fig. 1 is a structural block diagram of the present invention.

FIG. 2 is a distribution diagram of the UAV obstacle avoidance system of the present invention.

3 is a circuit diagram of a power module of the present invention.

FIG. 4 is a circuit diagram of a clock reset module of the present invention.

5 is a circuit diagram of an A/D conversion module of the present invention.

FIG. 6 is a circuit diagram of the ultrasonic transmitting unit of the present invention.

FIG. 7 is a circuit diagram of the ultrasonic receiving unit of the present invention.

FIG. 8 is a circuit diagram of an alarm module of the present invention.

FIG. 9 is a schematic diagram of the flight attitude angle of the present invention.

detailed description

As shown in Figure 1, in this embodiment, a vision-based obstacle avoidance system for plant protection UAVs includes:

In a further embodiment, as shown in Figure 2,

In a further embodiment,

In a further embodiment, as shown in FIG. 3 , the power module includes a capacitor C2, a capacitor C1, a power supply U1, a capacitor C4, a capacitor C3, and a capacitor C5.

In a further embodiment, one end of the capacitor C2 in the power module is respectively connected to one end of the capacitor C1, the input power supply 12V, the pin 1 and pin 3 of the power supply U1; the other end of the capacitor C2 is respectively connected to the capacitor C1 The other end is connected to the U1 pin 2 of the power supply; the U1 pin 5 of the power supply is respectively connected to one end of the capacitor C3 and the positive end of the capacitor C5; the other end of the capacitor C3 is connected to the negative end of the capacitor C5 and the ground wire GND respectively; The pin 4 of the power supply U1 is connected to the negative terminal of the capacitor C4; the positive terminal of the capacitor C4 is connected to the ground wire GND.

In a further embodiment, as shown in FIG. 4 , the clock reset module includes a button S1, a capacitor C6, a resistor R1, a transistor Q1, a resistor R2, a resistor R3, and a capacitor C7.

In a further embodiment, one end of the button S1 in the clock reset module is respectively connected to one end of the resistor R1 and the positive end of the capacitor C6; the other end of the button S1 is respectively connected to the negative end of the capacitor C6, one end of the resistor R3 and the capacitor C7 The negative terminal and the ground wire GND are connected; the other end of the resistor R1 is connected to the base terminal of the transistor Q1; the emitter terminal of the transistor Q1 is respectively connected to one end of the capacitor C2, one end of the capacitor C1, the input power supply 12V, and the pin 1 and pin of the power supply U1. 3 is connected; the collector terminal of the transistor Q1 is connected to one end of the resistor R2; the other end of the resistor R2 is respectively connected to the other end of the resistor R3 and the positive terminal of the capacitor C7.

In a further embodiment, as shown in FIG. 2 , the control unit includes a controller U2, and the pin 60 of the controller U2 is respectively connected to the other end of the resistor R2, the other end of the resistor R3, and the positive end of the capacitor C7; the The pin 5 of the controller U2 and the pin 5 of the power supply U1 are respectively connected with one end of the capacitor C3 and the positive end of the capacitor C5; the pin 7 of the controller U2 is respectively connected with one end of the button S1, one end of the resistor R1 and the positive end of the capacitor C6;

In a further embodiment, as shown in FIG. 7 , the ultrasonic receiving unit includes a resistor R9, a capacitor C19, a resistor R10, a resistor R8, a capacitor C18, and a receiver L1.

In a further embodiment, one end of the resistor R9 in the ultrasonic receiving unit is connected to the pin 62 of the controller U2; the other end of the resistor R9 is respectively connected to one end of the capacitor C19, one end of the resistor R10, and one end of the resistor R8; the The other end of the capacitor C19 is connected to the ground wire GND; the other end of the resistor R10 is connected to the controller U2 pin 581; the other end of the resistor R8 is connected to one end of the capacitor C18; the other end of the capacitor C18 is connected to one end of the receiver L1; The other end of the receiver L1 is connected to the ground wire GND.

In a further embodiment, as shown in FIG. 8 , the alarm module includes a resistor R7, a transistor Q5, and an alarm LS2.

In a further embodiment, one end of the resistor R7 in the alarm module is connected to the pin 50 of the controller U2; the other end of the resistor R7 is connected to the base end of the transistor Q5; the collector end of the transistor Q5 is connected to the alarm device One end of LS1 is connected; the other end of the alarm device LS1 is connected to the input power +12V; the emitter end of the transistor Q5 is connected to the ground wire GND.

In a further embodiment, as shown in FIG. 2 , the operation processing module includes an inductor L1 , a capacitor C9 , an inductor L2 , a diode D2 , a diode D1 , an inductor L3 , a capacitor C8 , and a processor U3 .

In a further embodiment, one end of the inductor L1 in the operation processing module is respectively connected to one end of the capacitor C9, one end of the inductor L2, and the ground wire GND; the other end of the inductor L1 is connected to the pin 9 of the processor U3; The other end of the capacitor C9 is connected with the processor U3 pin 10; the other end of the inductance L2 is connected with the processor U3 pin 11, and the processor U3 pins 23 and 18 are both connected with the ground GND; the processor The U3 pin 20 is connected to the positive terminal of the capacitor C8; the negative terminal of the capacitor C8 is connected to the ground wire GND; the processor U3 pin 1 is connected to one end of the inductor L3; the other end of the inductor L3 is connected to the ground wire GND; The processor U3 pin 4 is respectively connected with the controller U2 pin 7, one end of the button S1, one end of the resistor R1, and the positive end of the capacitor C6; the processor U3 pin 8 is connected with the negative end of the diode D2; the positive end of the diode D2 is connected; The terminals are respectively connected to the positive terminal of the diode D1, the pin 5 of the controller U2, and the pin 5 of the power supply U1 are respectively connected to one end of the capacitor C3 and the positive terminal of the capacitor C5.

In a further embodiment, as shown in FIG. 2 , the driving module includes a driver U4, a capacitor C10, a diode D5, a capacitor C12, a capacitor C13, and a capacitor C11.

In a further embodiment, the driver U4 pin 16 in the driver module is connected to the controller U2 pin 42; the driver U4 pin 13 is respectively connected to one end of the capacitor C12, the positive end of the diode D5, and the negative end of the diode D1. The extreme, the driver U4 pin 2 and pin 4, and one end of the capacitor C10 are connected; the other end of the capacitor C10 is connected to the ground wire GND; the other end of the capacitor C12 is respectively connected with one end of the capacitor C13, the driver U4 pin 11 and pin 9 , the ground wire is connected to GND; one end of the capacitor C11 is connected to the pin 12 of the driver U4; the other end of the capacitor C11 is connected to the pin 8 of the starter U4.

In a further embodiment, as shown in FIG. 5 , the A/D conversion module includes a capacitor C17 , a converter U5 , an inductor L4 , a diode D6 , a resistor R6 , an inductor L5 , a capacitor C15 , and a capacitor C16 .

In a further embodiment, the converter U5 pin 6 and pin 3 in the A/D conversion module are respectively connected to one end of the capacitor C17, one end of the inductor L4, and the processor U3 pin 24; the converter U5 pin 2 is respectively connected with the other end of the inductor L4 and the positive end of the diode D6; the converter U5 pin 5 is respectively connected with one end of the resistor R6, one end of the inductor L5 and one end of the capacitor C15; the converter U5 pin 4 is respectively connected with The other end of the capacitor C17, the other end of the resistor R6, one end of the capacitor C16, and the ground wire GND are connected; the other end of the capacitor C16 is connected to the other end of the capacitor C15, the other end of the inductor L5, the controller U2 pin 55, and the negative end of the diode D6.

In a further embodiment, as shown in FIG. 6 , the ultrasonic emitting unit includes a transistor Q4, a diode D3, a resistor R5, a diode D4, a resistor R5, a transistor Q3, a capacitor C14, a transistor Q2, a resistor R4, and a transmitter L2.

In a further embodiment, the collector terminal of the transistor Q4 in the ultrasonic transmitting unit is connected to the pin 23 of the processor U3; the base terminal of the transistor Q4 is connected to the negative terminal of the diode D3; the emitter terminal of the transistor Q4 is respectively Connect with the positive terminal of diode D4, the emitter terminal of transistor Q3, the emitter terminal of transistor Q2, and one end of transmitter L2; the positive terminal of diode D3 is respectively connected to one end of resistor R5, the collector terminal of transistor Q3, the negative terminal of diode D4, one terminal of capacitor C14, and one terminal of resistor R5. One end of R4 is connected to the collector end of the transistor Q2 and the negative end of the diode D5; the other end of the resistor R5 is connected to the base end of the transistor Q3 and the other end of the capacitor C14 respectively; the other end of the resistor R4 is respectively connected to the base end of the transistor Q2 and the transmitter L2 Connect the other end.

In a further embodiment, the capacitor C4, the capacitor C5, the capacitor C6, the capacitor C7, and the capacitor C8 are electrolytic capacitors; the diode D1, the diode D2, and the diode D5 The models are all Zener diodes; the transistor Q1 model is PNP; the transistor Q2, the transistor Q3, the transistor Q4, and the transistor Q5 are all NPN models; the power supply U1 model is MIC5219; the The model of the processor U3 is MPU6050; the model of the controller U2 is STM32; the model of the driver U4 is HMC5883L.

In a further embodiment, a vision-based obstacle avoidance method for a plant protection UAV obstacle avoidance system is characterized by the following steps:

In a further embodiment, as shown in FIG. 9 , a vision-based obstacle avoidance method for a plant protection UAV obstacle avoidance system is characterized in that the

steps

1 and 2 further obtain that the flight attitude angle and Kalman filter algorithm;

Steps 1-2, of which

The attitude matrix is represented as follows:

The flight attitude angle uses the quaternion method to calculate the attitude, and uses Q to represent the attitude quaternion, where Q=q ₀ +q ₁ i+q ₂ j+q ₃ k, q ₀ is true, q ₁ , q ₂ , q ₃ are imaginary numbers and ‖Q‖=1, and then the above method can be obtained:

Step 2-2, according to

Which leads to the following way:

P _k =AP _k-1 A ^T +Q

The way:

in

K=P _k H ^T /[HP _k H ^T +R]

The expression of the covariance matrix P′ _k is as follows:

P _k ′=(I-KH)P _k

where I is the identity matrix.

In a word, the present invention has the following advantages: the capacitor C1 and the

pins

1 and 3 of the power supply unit U1 provide a low-impedance path, and the capacitor C2 stores the obtained electric energy, thereby maintaining the stability of the operation of the power supply unit U1, and the output of the power supply unit U1 The terminal uses capacitor C4 and capacitor C3 to ground to filter out the interference band of the output terminal, and the clock module uses the frequency stability of the crystal oscillator to generate a series of stable frequency signals through the inverter and the oscillator circuit, and then adjusts the frequency signal as the system clock. The reset circuit uses the resistor R1 and the capacitor C6 to charge and discharge, while the capacitor C8 in the operation processing module is grounded to filter the interference signal during the operation of the processor U3, while the inductor L1 and the inductor L2 are used to filter the transmission signal, thereby improving the detection signal. Diode D5, diode D2 and diode D1 are used for unidirectional transmission of voltage to prevent reverse transmission of voltage when the device is powered off; while the ultrasonic transmitting unit and receiving unit use ultrasonic ranging according to the speed of sound and ultrasonic transmission, The received time interval judges and estimates the obstacles and the distance between the obstacles and the obstacles during the flight of the drone, and then accurately judges, and then makes adjustments through the alarm prompt, and then automatically adjusts the flight trajectory to complete the specified flight task. .

In addition, it should be noted that each specific technical feature described in the above-mentioned specific implementation manner may be combined in any suitable manner under the circumstance that there is no contradiction. In order to avoid unnecessary repetition, the present invention will not describe various possible combinations.

Claims

A vision-based plant protection UAV obstacle avoidance system, characterized in that it includes the following modules:

A power supply module for transmitting the adjusted output power to the control module and the sensor measurement module, thereby providing a power source for the UAV obstacle avoidance system module;

A control module for receiving the detection signal fed back by the sensor measurement module, so as to control the acquired detection signal, and then convey different control instructions;

A sensor measurement module for judging and estimating the obstacles and the distances between the obstacles and the obstacles during the flight of the UAV according to the speed of the ultrasonic waves and the time interval of ultrasonic transmission and reception through the ultrasonic ranging method.
The vision-based obstacle avoidance system for plant protection drones according to claim 1, wherein the power supply module comprises a power supply module and a clock reset module, wherein the power supply module comprises a capacitor C2, a capacitor C1, a power supply U1, capacitor C4, capacitor C3, capacitor C5, wherein one end of the capacitor C2 is respectively connected with one end of the capacitor C1, the input power supply 12V, the pin 1 and pin 3 of the power supply U1; the other end of the capacitor C2 is respectively connected with the capacitor C1 The other end is connected to the U1 pin 2 of the power supply; the U1 pin 5 of the power supply is respectively connected to one end of the capacitor C3 and the positive end of the capacitor C5; the other end of the capacitor C3 is connected to the negative end of the capacitor C5 and the ground wire GND respectively; The pin 4 of the power supply U1 is connected to the negative terminal of the capacitor C4; the positive terminal of the capacitor C4 is connected to the ground wire GND.
A vision-based plant protection drone obstacle avoidance system according to claim 2, wherein the clock reset module comprises a button S1, a capacitor C6, a resistor R1, a transistor Q1, a resistor R2, a resistor R3, and a capacitor C7 , wherein one end of the button S1 is respectively connected with one end of the resistor R1 and the positive end of the capacitor C6; the other end of the button S1 is respectively connected with the negative end of the capacitor C6, one end of the resistor R3, the negative end of the capacitor C7, and the ground wire GND; the resistor R1 The other end is connected with the base end of the transistor Q1; the emitter end of the transistor Q1 is respectively connected with one end of the capacitor C2, one end of the capacitor C1, the input power supply 12V, the pin 1 and pin 3 of the power supply U1; the collector end of the transistor Q1 is connected with the resistor One end of R2 is connected; the other end of the resistor R2 is connected to the other end of the resistor R3 and the positive end of the capacitor C7 respectively.
A vision-based plant protection UAV obstacle avoidance system according to claim 1, wherein the control module comprises a control unit, an ultrasonic receiving unit, and an alarm module, wherein the control unit comprises a controller U2, and the The controller U2 pin 60 is respectively connected with the other end of the resistor R2, the other end of the resistor R3, and the positive terminal of the capacitor C7; Extreme connection; the controller U2 pin 7 is respectively connected with one end of the button S1, one end of the resistor R1, and the positive end of the capacitor C6;

The ultrasonic receiving unit includes a resistor R9, a capacitor C19, a resistor R10, a resistor R8, a capacitor C18, and a receiver L1, wherein one end of the resistor R9 is connected to the controller U2 pin 62; the other end of the resistor R9 is respectively connected to the capacitor C19 One end, one end of the resistor R10, and one end of the resistor R8 are connected; the other end of the capacitor C19 is connected to the ground wire GND; the other end of the resistor R10 is connected to the pin 581 of the controller U2; the other end of the resistor R8 is connected to one end of the capacitor C18; The other end of the capacitor C18 is connected to one end of the receiver L1; the other end of the receiver L1 is connected to the ground wire GND;

The alarm module includes a resistor R7, a transistor Q5 and an alarm LS2, wherein one end of the resistor R7 is connected to the controller U2 pin 50; the other end of the resistor R7 is connected to the base terminal of the transistor Q5; the collector terminal of the transistor Q5 One end of the alarm device LS1 is connected; the other end of the alarm device LS1 is connected to the input power +12V; the emitter end of the transistor Q5 is connected to the ground wire GND.
A vision-based plant protection UAV obstacle avoidance system according to claim 1, wherein the sensor measurement module comprises an operation processing module, a driving module, an A/D conversion module, and an ultrasonic transmitting unit, wherein the The operation processing module includes an inductor L1, a capacitor C9, an inductor L2, a diode D2, a diode D1, an inductor L3, a capacitor C8, and a processor U3, wherein one end of the inductor L1 is respectively connected to one end of the capacitor C9, one end of the inductor L2, and the ground wire GND; The other end of the inductance L1 is connected to the processor U3 pin 9; the other end of the capacitor C9 is connected to the processor U3 pin 10; the other end of the inductance L2 is connected to the processor U3 pin 11. The processor U3 Pins 23 and 18 are both connected to the ground wire GND; the processor U3 pin 20 is connected to the positive terminal of the capacitor C8; the negative terminal of the capacitor C8 is connected to the ground wire GND; the processor U3 pin 1 is connected to the inductor L3 One end is connected; the other end of the inductor L3 is connected to the ground wire GND; the pin 4 of the processor U3 is respectively connected to the pin 7 of the controller U2, one end of the button S1, one end of the resistor R1, and the positive end of the capacitor C6; Pin 8 of U3 is connected to the negative terminal of diode D2; the positive terminal of diode D2 is respectively connected to the positive terminal of diode D1, the pin 5 of controller U2, and the pin 5 of power supply U1 are respectively connected to one end of capacitor C3 and the positive terminal of capacitor C5.
The vision-based obstacle avoidance system for plant protection drones according to claim 5, wherein the drive module comprises a driver U4, a capacitor C10, a diode D5, a capacitor C12, a capacitor C13, and a capacitor C11, wherein the The driver U4 pin 16 is connected to the controller U2 pin 42; the driver U4 pin 13 is respectively connected to one end of the capacitor C12, the positive end of the diode D5, the negative end of the diode D1, the driver U4 pin 2 and pin 4, and one end of the capacitor C10. The other end of the capacitor C10 is connected to the ground wire GND; the other end of the capacitor C12 is respectively connected to one end of the capacitor C13, the driver U4 pin 11 and pin 9, and the ground wire GND; one end of the capacitor C11 is connected to the driver U4 lead Pin 12 is connected; the other end of the capacitor C11 is connected to pin 8 of the starter U4.
The vision-based obstacle avoidance system for plant protection drones according to claim 5, wherein the A/D conversion module comprises a capacitor C17, a converter U5, an inductor L4, a diode D6, a resistor R6, and an inductor L5 , capacitor C15, capacitor C16, wherein the converter U5 pin 6 and pin 3 are respectively connected with one end of the capacitor C17, one end of the inductor L4, and the processor U3 pin 24; the converter U5 pin 2 is respectively connected with the inductor L4 The other end is connected to the positive end of the diode D6; the pin 5 of the converter U5 is respectively connected to one end of the resistor R6, one end of the inductor L5, and one end of the capacitor C15; the pin 4 of the converter U5 is respectively connected to the other end of the capacitor C17 and the other end of the resistor R6. One end of the capacitor C16 is connected to the ground wire GND; the other end of the capacitor C16 is connected to the other end of the capacitor C15, the other end of the inductor L5, the pin 55 of the controller U2, and the negative end of the diode D6.
A vision-based plant protection drone obstacle avoidance system according to claim 5, wherein the ultrasonic transmitting unit comprises a transistor Q4, a diode D3, a resistor R5, a diode D4, a resistor R5, a transistor Q3, and a capacitor C14 , transistor Q2, resistor R4, transmitter L2, wherein the collector terminal of the transistor Q4 is connected with the processor U3 pin 23; the base terminal of the transistor Q4 is connected with the negative terminal of the diode D3; the emitter terminal of the transistor Q4 is respectively connected with the diode The positive terminal of D4, the emitter terminal of the transistor Q3, the emitter terminal of the transistor Q2, and one end of the transmitter L2 are connected; the positive terminal of the diode D3 is respectively connected to one end of the resistor R5, the collector terminal of the transistor Q3, the negative terminal of the diode D4, the one end of the capacitor C14, and one end of the resistor R4. , the collector terminal of transistor Q2 and the negative terminal of diode D5 are connected; the other end of the resistor R5 is respectively connected with the base terminal of the transistor Q3 and the other end of the capacitor C14; the other end of the resistor R4 is respectively connected with the base terminal of the transistor Q2 and the other end of the transmitter L2 connect.
A vision-based obstacle avoidance method for a plant protection UAV obstacle avoidance system, characterized by the following steps:

Step 1. The operation processing module first measures its own attitude information through the processor U3, and then converts the measured three-axis angular velocity and acceleration attitude information into digital signals through the A/D conversion module, and then transmits the digital signals to the control module for processing. deal with;

Step 2. The drive module controls the heading and orientation of the drone through the change of the ultrasonic ranging sensor, and the driver U4 uses the anisotropic magnetoresistive technology to measure the direction and size of the earth's magnetic field, and the driver U4 pin is connected to the capacitor C11, The function of the capacitor C11 is to filter, thereby improving the response of the drive operation. The capacitor C13 is used as a storage device to provide the driver U4 with starting power, which reduces the voltage shock caused by instantaneous startup.
The obstacle avoidance method of a vision-based plant protection UAV obstacle avoidance system according to claim 9, wherein the step 1 and the step 2 further obtain, the flight attitude angle and the Kalman filter algorithm;

Step 1-1. The flight attitude angle includes roll angle, pitch angle and yaw angle, and the roll angle is the angle between the longitudinal symmetry plane of the body and the longitudinal vertical plane.
Indicates that the pitch angle is the angle between the longitudinal axis of the body and the longitudinal horizontal axis, expressed by θ, and the yaw angle is the angle between the projection of the longitudinal axis of the body on the horizontal plane xoy and the prime meridian in the geographic coordinate system, denoted by ω Therefore, the conversion from the earth coordinate system to the body coordinate system can be realized by three rotations, and the conversion formula is as follows:

Steps 1-2, of which
The attitude matrix is represented as follows:

The flight attitude angle uses the quaternion method to calculate the attitude, and uses Q to represent the attitude quaternion, where Q=q 0 +q 1 i+q 2 j+q 3 k, q 0 is true, q 1 , q 2 , q 3 are imaginary numbers and ‖Q‖=1, and then the above method can be obtained:

Steps 1-3, and then according to the substitution of the above two sets of equations, the relationship between the flight attitude angle and the quaternion can be obtained, and the equation is as follows:

Steps 1-4, and then the differential equation of the attitude quaternion Q is obtained as follows:

Where Q 0 is a predetermined initial quaternion, ω x, ω y, ω z are x, y, z-axis output angular velocity, and thus can obtain the current quaternion Q i in accordance with step 1-4, the step of substituting Q i 1-3 can then obtain the flight attitude angle information at the current moment;

Step 2-1. According to the Kalman filter algorithm, set the current sampling time as k, the last moment as k-1, and the optimal state as
Then according to the Kalman filter algorithm, the following steps are obtained:

Step 2-2, according to
Predict the current state of the obstacle avoidance system, and the predicted value is recorded.
Which leads to the following way:

Wherein A represents a state transition matrix matrix, u k represents the current time input, the system matrix B denotes the control matrix avoidance,
It consists of two parts, one part is the product between the optimal state at the previous moment and matrix A, and the other part is the product between the input quantity at the current moment and matrix B;

Step 2-3, using the covariance matrix equation, and setting the current state matrix as P k , the following methods can be obtained:

P k =AP k-1 A T +Q

where P k-1 is the optimal solution estimated by the covariance matrix at the previous moment, and Q is the inherent noise matrix of the prediction model;

Step 2-3, set the current observation value as z k , the current observation matrix as H, and the covariance matrix of the observation noise as R, the following methods can be obtained:

Thus, the predicted value and the observed value are fused to obtain the optimal estimated value of the current state.
The way:

in
Represents the residual between the actual observed value and the predicted value, K is called the Kalman coefficient matrix, and K is expressed as:

K=P k H T /[HP k H T +R]

Among them, the value of K directly affects the proportion of the observed value and the predicted value. The larger the K is, the larger the weighted coefficient of the observed value is, and vice versa; the larger the predicted value;

In order to ensure the recursive operation of the algorithm, it is necessary to update the current optimal estimated value in real time.
The expression of the covariance matrix P′ k is as follows:

P' k =(I-KH)P k

where I is the identity matrix.