CN211956224U

CN211956224U - Cable inspection aircraft based on laser radar and vision

Info

Publication number: CN211956224U
Application number: CN202020894363.5U
Authority: CN
Inventors: 刘正武; 王庭蔚; 周立青
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2020-11-17
Anticipated expiration: 2030-05-25

Abstract

The utility model relates to an aircraft technique, in particular to a cable inspection aircraft based on laser radar and vision, which comprises a controller and an aircraft, wherein the controller comprises a microprocessor module, and a 12V and 5V voltage reduction module, an attitude angle measurement module, a height measurement module, a position measurement module, a signal lamp module, a vision processing module and a wireless communication module which are electrically connected with the microprocessor module; the aircraft comprises a microprocessor, a brushless motor and an electric regulator, wherein the microprocessor is electrically connected with the electric regulator and controls the electric regulator to output through a PWM (pulse width modulation) wave, and the electric regulator is electrically connected with the brushless motor. This aircraft also can normally work in the place that indoor and GPS signal are weak, carries out image processing with OPENMV simultaneously, has alleviateed the burden of aircraft to a certain extent, has carried out a series of image processing to the image on OPENMV and has strengthened interference immunity, and wireless communication module and signal lamp module can let the operator learn the state of aircraft more easily to reduce user's the operation degree of difficulty.

Description

Cable inspection aircraft based on laser radar and vision

Technical Field

The utility model belongs to the technical field of the aircraft, especially, relate to a cable inspection aircraft based on laser radar and vision.

Background

Four propellers of the four-axis aircraft are simple mechanisms with directly connected motors, and the cross-shaped layout allows the aircraft to obtain the force for rotating the aircraft body by changing the rotating speed of the motors, so that the self posture of the aircraft can be adjusted. Because of its inherent complexity, historically there have never been large commercial quadrotors. In recent years, due to the development of micro-electromechanical control technology, the stable four-axis aircraft has attracted extensive attention, and the application prospect is very considerable.

The overhead line is a very common line for power transmission in China at present, however, due to the influence of various factors, the safe operation of the overhead line is easily threatened by various conditions, so that the cable patrol aircraft is a key point of attention in various circles in recent years, and due to the danger and difficulty of high-altitude operation, the cable patrol aircraft is very necessary to perform troubleshooting on the cable to replace manpower. Domestic papers on cable patrol are still very few, and existing solutions based on such problems are relatively crude, so that further research on cable patrol aircrafts is necessary.

Aircraft can be divided into fixed wing aircraft, single rotor aircraft and multi-rotor aircraft.

The fixed wing aircraft generates forward power by means of a propulsion system, so that the aircraft can move forward quickly. After the airplane obtains the forward speed, the air flow acts on the wingspan of the airplane to generate a rising pulling force, and when the pulling force is greater than the gravity of the airplane body, the airplane is in a rising flight state. The left-right balance of the fixed wing flying depends on the size of the sweep angle of the left-right main wing, the front-back balance depends on the sweep angle of the tail rudder, the direction depends on the vertical tail rudder, and in addition, the course of the fixed wing airplane is usually completed by the combined actions of rolling and pitching. Its advantages are long endurance time and high speed, but it also has the disadvantage of not being able to take off and land vertically.

The single-rotor helicopter is also called a helicopter, and the main power system of the helicopter is only provided with a large-sized propeller and mainly used for providing ascending power for flying, so that when the ascending power is larger than the gravity of a helicopter body, the helicopter is in an ascending state. And because the helicopter only has one main power propeller, when the main power motor rotates at a high speed, the rotation of the propeller can generate counter torque to the helicopter body. Under the action of the counter-torque, the aircraft can spin in the direction opposite to the rotation direction of the propeller. In order to solve the problem of the self-rotation of the helicopter, a small propeller in the horizontal direction is required to be added at the tail part of the airplane, the generated pulling force is mainly used for offsetting the self-rotation of the airplane body, and when the helicopter needs to change the heading direction, the helicopter can also be adjusted through the tail propeller. In addition to the main power motor and the tail motor, three steering engines are usually provided for changing the pitch of the main power propeller to generate roll and pitch attitudes in the fuselage, thereby enabling the aircraft to fly forward and backward or left and right. Its advantages are vertical taking off and landing, hovering in air, short endurance time, complex mechanical structure, high control difficulty and low flying speed.

A multi-rotor helicopter is an unmanned aerial vehicle consisting of three, four or more propellers. The most typical and common is the quad-rotor helicopter. The four rotors have four shafts, four propellers are arranged, and the vertical take-off and landing can be realized by upward pulling force generated by the high-speed rotation of the propellers. However, unlike a helicopter, the forward, reverse, left and right flight of multiple rotors is based on different rotational speeds of the four propellers, rather than on changing the pitch of the main power propellers as in a helicopter, because the pitch of the four rotor propellers is fixed and the size of the propellers is also fixed. The wheelbases of the four shafts of the four rotors are also generally the same, so the power system is also generally symmetrical. Three, six, eight or other multi-rotors are not substantially different from four rotors, except for the distribution of power and torque to the plurality of propellers. Its advantages are vertical lifting and hovering, simple structure and flexible operation. But the defects are also obvious, namely short endurance time and slow flying speed.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an use TM4C123GH6PM of TI to carry on high definition camera and laser radar as the four rotor crafts of master control singlechip, the aircraft of patrolling and examining of line and troubleshooting is carried out the cable based on vision and laser radar technique.

In order to achieve the above object, the utility model adopts the following technical scheme: a cable inspection aircraft based on laser radar and vision comprises a controller and an aircraft, wherein the controller comprises a microprocessor module, and a 12V voltage reduction module, a 5V voltage reduction module, an attitude angle measurement module, a height measurement module, a position measurement module, a signal lamp module, a vision processing module and a wireless communication module which are electrically connected with the microprocessor module; the aircraft comprises a microprocessor, a brushless motor and an electric regulator, wherein the microprocessor is electrically connected with the electric regulator and controls the electric regulator to output through a PWM (pulse width modulation) wave, and the electric regulator is electrically connected with the brushless motor.

In the cable patrol aircraft based on the laser radar and vision, the attitude angle measurement module comprises an ICM20602 and an AK8975, and the communication mode with the microprocessor is SPI communication.

In the cable patrol aircraft based on the laser radar and vision, the height measurement module comprises an SPL06 and an US-100, the communication mode of the SPL06 and the microprocessor is SPI communication, and the communication mode of the US-100 and the microprocessor is serial communication.

In the cable patrol aircraft based on the laser radar and vision, the position measurement module comprises an rpidar, an LC306 and an ICM20602, the LC306 and the microprocessor are communicated in a serial port mode, and the ICM20602 and the microprocessor are communicated in an SPI mode.

In the cable patrol aircraft based on the laser radar and the vision, the signal lamp module is a high-power RGB lamp.

In the above cable patrol aircraft based on the laser radar and the vision, the vision processing module is OPENMV, and the OPENMV is in serial port communication with the microprocessor in a communication mode.

In the cable patrol aircraft based on the laser radar and vision, the wireless communication module adopts HC-05, the communication mode of HC-05 and the microprocessor is serial port communication, and meanwhile, the remote PC is also provided with HC-05 for wireless transparent transmission.

In the above described lidar and vision based cable patrol aircraft, the microprocessor employs TI TM4C123GH6 PM.

The utility model has the advantages that: compare in the aircraft that relies on GPS to carry out the location, the utility model discloses an aircraft also can normally work in the place that indoor and GPS signal are weak, carries out image processing rather than handling on microprocessor with OPENMV simultaneously, has alleviateed the burden of aircraft to a certain extent, and simultaneously, has carried out a series of image processing and has strengthened the interference immunity of this system to the image on OPENMV, and wireless communication module and signal lamp module can let the operator learn the state of aircraft more easily to reduce user's the operation degree of difficulty. And the utility model discloses the aircraft still has positioning accuracy height, reaches centimeter level precision positioning, and the interference immunity is strong in the vision processing, the strong advantage of robustness.

Drawings

Fig. 1 is a block diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a schematic diagram of a microprocessor according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a 5V voltage reduction module according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a 12V step-down module according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an attitude angle measurement module and a position strategy module ICM20602 according to an embodiment of the present invention;

fig. 6 is a schematic diagram of an attitude angle measurement module AK8975 according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a height measuring module SPL06 according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a serial port interface according to an embodiment of the present invention;

fig. 9 is a schematic diagram of an embodiment of the RGB lamp of the signal lamp module of the present invention;

fig. 10 is a schematic diagram of a PWM output according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The embodiment provides a four-rotor aircraft taking TM4C123GH6PM of TI as a main control single chip microcomputer to carry a high-definition camera and a laser radar, and the four-rotor aircraft comprises a controller and an aircraft, wherein the controller comprises a microprocessor module, and a 12V and 5V voltage reduction module, an attitude angle measurement module, a height measurement module, a position measurement module, a signal lamp module, a vision processing module and a wireless communication module which are electrically connected with the microprocessor module. The aircraft comprises a microprocessor, a brushless motor and an electric regulator, wherein the microprocessor is electrically connected with the electric regulator and controls the electric regulator to output through a PWM (pulse width modulation) wave, the electric regulator is electrically connected with the brushless motor, and the rotating speed of the brushless motor is determined by the output of the electric regulator.

The 12V and 5V voltage reduction modules are used for reducing the voltage 12V provided by the model airplane battery into 5V and 3.3V and supplying power to the microprocessor and each module.

The attitude angle measurement module comprises an ICM20602 and an AK8975, the communication mode with the microprocessor is SPI communication, the attitude angle measurement module acquires a gyroscope sent by the ICM20602 in real time, an accelerometer signal and a magnetometer signal sent by the AK8975 are sent to the microprocessor, zero drift correction is firstly carried out, namely, after the data are acquired by horizontal standing for a period of time, an average value is taken, namely, a zero drift value is obtained, the data acquired subsequently are subtracted from the zero drift value, namely, a zero drift correction value is obtained, the gyroscope data and the accelerometer data are subjected to complementary filtering, then, the output value of a complementary filter is subjected to yaw correction by the magnetometer data, and finally the real-time Euler angles (namely, a roll angle, a pitch angle and a yaw angle) of the aircraft can be obtained and participate in subsequent self-stabilizing.

The height measurement module comprises an SPL06 and an US-100, the communication mode of the SPL06 and the microprocessor is SPI communication, the communication mode of the US-100 and the microprocessor is serial port communication, the height measurement module collects barometer signals sent by the SPL06 and ultrasonic signals sent by the US-100 in real time and sends the barometer signals to the microprocessor, zero drift correction is firstly carried out, the air pressure value of the barometer on the ground is recorded, the ground height of the aircraft can be obtained by multiplying the air pressure difference value and the coefficient during flight, a height switching strategy is formulated according to the characteristics of two different sensors, the aircraft adopts ultrasonic waves to measure height during low-altitude flight, and the aircraft adopts the barometer to measure height during high-altitude flight.

The position measurement module comprises an rplidar, an LC306 and an ICM20602, the communication mode of the LC306 and the microprocessor is serial port communication, the mode of the ICM20602 and the microprocessor is SPI communication, the position measurement module collects an optical flow signal sent by the LC306 and an accelerometer signal sent by the ICM20602 in real time and sends the optical flow signal and the accelerometer signal to the microprocessor, the microprocessor performs rotation compensation on an optical flow value by using a real-time Euler angle, then uses the product of an output value and a height coefficient as a transverse moving distance, combines the transverse acceleration of the aircraft under a world coordinate system obtained after the accelerometer signal is processed, performs fusion by using a Kalman filter, and calculates the real-time space coordinate of the aircraft, however, the position obtained by the mileage has accumulated error, the error is increased along with the increase of time, laser radar data is added, live SLAM mapping can be performed on the periphery of the aircraft by using the point cloud data obtained by the laser radar and the data output by the Kalman, therefore, centimeter-level precision positioning and navigation can be realized indoors or in places with weak GPS signals.

The signal lamp module adopts a high-power RGB lamp, and the microprocessor is combined with the real-time condition output of the aircraft, so that an operator can judge the running state of the aircraft through the color of the lamp, and if the aircraft breaks down or finds a cable fault, the operator can know the running state through the color of the lamp and carry out corresponding processing.

The vision processing module adopts OPENMV, the OPENMV is in serial port communication with the microprocessor in a communication mode, the OPENMV collects RGB image signals shot by the cable in real time, meanwhile, the images are subjected to image processing of binarization, Gaussian smoothing, corner feature extraction, color threshold extraction, edge extraction and Hough transformation, extracted information is comprehensively scored, therefore, evaluation of the shot cable is obtained, and if the evaluation of the cable is lower than a certain threshold value, the signals are sent to the microprocessor.

The wireless communication module adopts HC-05, the communication mode of HC-05 and microprocessor is serial port communication, meanwhile, the remote PC is also provided with HC-05 for wireless transparent transmission, the wireless communication module collects the control information frame sent from the remote end in real time and sends the state information frame of the aircraft, both sides can update the control information and the state information after passing through the communication protocol, and the remote control of an operator is facilitated.

The microprocessor module is mainly used for establishing a complete serial-parallel stage PID controller aiming at various data, inputting the various data into the PID controller and converting the final output into the duty ratio of PWM waves, thereby achieving the effect of controlling the rotating speed of the motor.

In specific implementation, as shown in fig. 1, the cable patrol flight system based on the laser radar and vision comprises a controller and an aircraft, wherein the controller comprises a microprocessor module, and a 12V and 5V voltage reduction module, an attitude angle measurement module, an altitude measurement module, a position measurement module, a signal lamp module, a vision processing module and a wireless communication module which are electrically connected with the microprocessor module. The aircraft comprises a microprocessor, a brushless motor and an electric regulator, wherein the microprocessor is electrically connected with the electric regulator and controls the electric regulator to output through a PWM (pulse width modulation) wave, the electric regulator is electrically connected with the brushless motor, and the rotating speed of the brushless motor is determined by the output of the electric regulator.

As shown in fig. 2, the microprocessor of the cable patrol flight system based on the laser radar and the vision in this embodiment adopts TM4C123GH6PM of TI, and the leading-out is a mode of being electrically connected with each module, including GPIO, SPI, PWM, and serial port.

As shown in fig. 3 and 4, the voltage reduction module of 12V and 5V is adopted in the present embodiment to reduce the voltage 12V provided by the model airplane battery to 5V and 3.3V for supplying power to the microprocessor and each module.

As shown in fig. 5 and 6, in this embodiment, the ICM20602 and the AK8975 are used as attitude angle measurement modules, the attitude angle measurement module collects a gyroscope sent by the ICM20602 in real time, an accelerometer signal and a magnetometer signal sent by the AK8975 are sent to a microprocessor, zero drift correction is performed first, that is, after data is collected for a period of time by horizontal standing, an average value is taken, that is, a zero drift value is obtained, the subsequent collected data is subtracted from the zero drift value, that is, a zero drift correction value is obtained, complementary filtering is performed on the gyroscope data and the accelerometer data, yaw correction is performed on the output value of a complementary filter by the magnetometer data, and finally real-time euler angles (roll angle, pitch angle and yaw angle) of the aircraft can be obtained and input to the self-stabilized PID controller.

As shown in fig. 7 and 8, in the embodiment, the SPL06 and the US-100 are used as height measuring modules, the ultrasonic module is an independent integrated module, a merchant does not open a source schematic diagram, and uses a serial port for connection, only a serial port schematic diagram is shown, the measuring module collects barometer signals sent by the SPL06 and ultrasonic signals sent by the US-100 in real time and sends the barometer signals to a microprocessor, zero drift correction is firstly performed and the air pressure value of the barometer on the ground is recorded, the ground height of the aircraft can be obtained by the product of the air pressure difference value and the coefficient during flight, a height switching strategy is formulated according to the characteristics of two different sensors, the aircraft adopts ultrasonic waves for height measurement during low-altitude flight, and the aircraft adopts the barometer for height measurement during high-altitude flight.

As shown in fig. 5 and 8, in the embodiment, the rpidar, the LC306 and the ICM20602 are used as position measurement modules, since the rpidar and the LC306 are independent integrated modules, a merchant does not open a source schematic diagram, uses serial ports for connection, only displays a serial port schematic diagram, the position measurement module collects an optical flow signal sent by the LC306 and an accelerometer signal sent by the ICM20602 in real time and sends the optical flow signal and the accelerometer signal to a microprocessor, the microprocessor performs rotation compensation on an optical flow value by using a real-time euler angle, then uses a product of a kalman output value and a height coefficient as a transverse moving distance, combines the accelerometer signal to process the transverse acceleration of the aircraft under a world coordinate system, performs fusion by using a kalman filter, calculates a real-time space coordinate of the aircraft, and adds laser radar data, and obtains point cloud data and data output by the laser radar to perform live SLAM mapping on the periphery of the aircraft, the mapping algorithm utilizes a point cloud filtering principle to map, and particularly the mapping algorithm is Gmapping, so that the position of the aircraft is output.

As shown in fig. 9, in the present embodiment, a high-power RGB is used as a signal lamp module, and the signal lamp module is output by a microprocessor in combination with the real-time condition of the aircraft, and if the aircraft has a low voltage, a red light is quickly turned on, if a fault is found, a yellow light is double-flashed, and if no fault is found and the aircraft is operating normally, a green light is turned on.

As shown in fig. 8, OPENMV is used as a visual processing module in this embodiment, since OPENMV is an independent integrated module, a merchant does not open a source schematic diagram, and only displays a serial schematic diagram by serial connection, OPENMV collects RGB image signals captured by a cable in real time, and simultaneously performs image processing of binarization, gaussian smoothing, corner feature extraction, color threshold extraction, edge extraction, and hough transformation on the image, scores information of each item of extraction, then averages, and takes the average as an evaluation of capturing the cable, and if the evaluation of the cable is lower than a certain threshold, sends a signal to a microprocessor.

As shown in fig. 8, in the embodiment, HC-05 is used as a wireless communication module, since HC-05 is an independent integrated module, a merchant does not open a source schematic diagram, and uses a serial port for connection, only the serial port schematic diagram is displayed, meanwhile, HC-05 is also arranged at a remote PC for wireless transparent transmission, the wireless communication module collects a control information frame sent from the remote end in real time and sends a status information frame of an aircraft, and both sides can update the control information and the status information after passing through a communication protocol. The control information includes: a takeoff frame, a pending frame, a working frame and a return frame. The state information specifically includes: low voltage frames, aircraft fault frames, cable fault frames, and normal status frames.

As shown in fig. 10, the present embodiment provides eight PWM channels for controlling the rotation speed of the brushless motor, and can be used to support the control of four-rotor, six-rotor and eight-rotor aircrafts, and the resource is rich and the adaptability is strong.

The PID controller of the aircraft is output in a three-way parallel mode by a self-stabilizing PID controller, a position PID controller and a height PID controller, and each PID controller is divided into multiple loops in a cascade relation.

The self-stabilization PID controller is divided into an angular velocity ring and an angle ring, gyroscope data and expected angular velocity output by the attitude angle measurement module are input into the angular velocity ring, then the output of the angular velocity ring is used as feedforward, the Euler angle data and the expected angle output by the attitude angle measurement module are input into the angle ring, and finally the output of the angle ring is used as a part of total PWM output. And the self-stability of the aircraft can be realized by respectively adjusting the PID parameters of the double rings.

The position PID controller is divided into an acceleration ring, a speed ring and a displacement ring, the acceleration data output by the position measurement module and the expected acceleration are input into the acceleration ring, then the output of the acceleration loop is used as feedforward, and the optical flow data after angle compensation and the expected speed are input into the speed loop, meanwhile, the integral of the optical flow velocity is used as point cloud data of a speedometer and a radar to be input into a Gmapping algorithm, the position data of the aircraft is output, finally, the output of a velocity loop is used as feedforward, and inputting the position data and the expected position of the aircraft output by Gmapping into a displacement ring, finally taking the output of the displacement ring as a part of the total PWM output, respectively adjusting PID (proportion integration differentiation) parameters of an acceleration ring and a speed ring to realize the positioning of the aircraft, then adjusting the PID parameters of the displacement ring, and identifying the position of the aircraft from a cable by combining point cloud data to realize the position control of keeping a certain distance between the aircraft and the cable and patrolling.

The altitude PID controller is divided into an acceleration ring, a speed ring and an altitude ring, acceleration data and expected acceleration output by the attitude angle measuring module are input into the acceleration ring, then the output of the acceleration ring is used as feedforward and input into the speed ring together with the time differential of ultrasonic data or barometer, namely vertical speed, and the expected speed, then a Kalman filter is used for predicting the acceleration and the vertical speed, the acceleration and the vertical speed are fused with the ultrasonic data or barometer data, altitude is output, the output of the speed ring is used as feedforward and input into the altitude ring together with the output of the Kalman filter and the expected altitude, finally the output of the altitude ring is used as a part of total PWM output, and the three-ring PID parameters are respectively adjusted to realize the hovering of the aircraft.

And finally, the total PWM output is the product of the sum of the outputs of the three PID controllers and the coefficient.

It should be understood that parts of the specification not set forth in detail are well within the prior art.

Although specific embodiments of the present invention have been described above with reference to the accompanying drawings, it will be appreciated by those skilled in the art that these embodiments are merely illustrative, and that various changes or modifications may be made without departing from the spirit and scope of the invention. The scope of the present invention is limited only by the appended claims.

Claims

1. A cable inspection aircraft based on laser radar and vision is characterized by comprising a controller and an aircraft, wherein the controller comprises a microprocessor module, and a 12V and 5V voltage reduction module, an attitude angle measurement module, a height measurement module, a position measurement module, a signal lamp module, a vision processing module and a wireless communication module which are electrically connected with the microprocessor module; the aircraft comprises a microprocessor, a brushless motor and an electric regulator, wherein the microprocessor is electrically connected with the electric regulator and controls the electric regulator to output through a PWM (pulse width modulation) wave, and the electric regulator is electrically connected with the brushless motor.

2. The lidar and vision based cable patrol aircraft of claim 1, wherein the attitude angle measurement module comprises ICM20602 and AK8975, and the communication mode with the microprocessor is SPI communication.

3. The lidar and vision based cable patrol aircraft of claim 1, wherein the altitude measurement module comprises SPL06 and US-100, the SPL06 is in SPI communication with the microprocessor, and the US-100 is in serial port communication with the microprocessor.

4. The lidar and vision based cable patrol aircraft according to claim 1, wherein the position measurement module comprises an rpidar, an LC306 and an ICM20602, the LC306 and the microprocessor communicate in a serial port manner, and the ICM20602 and the microprocessor communicate in an SPI manner.

5. The lidar and vision based cable patrol aircraft of claim 1, wherein the signal lamp module is a high power RGB lamp.

6. The lidar and vision based cable patrol aircraft according to claim 1, wherein the vision processing module is OPENMV, and the OPENMV is in serial communication with the microprocessor.

7. The cable patrol aircraft based on lidar and vision as claimed in claim 1, wherein the wireless communication module adopts HC-05, the communication mode of HC-05 and the microprocessor is serial port communication, and HC-05 is also provided at the remote PC for wireless transparent transmission.

8. The lidar and vision based cable patrol vehicle of claim 1, wherein the microprocessor employs TI TM4C123GH6 PM.