Device and method for stabilizing remote sensing equipment posture and obtaining its external orientation elements

Abstract

The present invention provides a device and method for stabilizing the attitude of remote sensing equipment and obtaining its external orientation elements. In the device, a gyro-stabilized platform is fixedly connected to a remote sensing aircraft; an IMU is fixedly connected to the remote sensing equipment; a GNSS antenna is fixedly connected to the top of the remote sensing aircraft; a positioning and orientation system is fixedly connected to an equipment cabinet; a control terminal is fixedly connected to the equipment cabinet; the IMU is connected to the positioning and orientation system through a data cable; the remote sensing equipment is connected to the gyro-stabilized platform, an industrial computer, and a positioning and orientation system through a data cable; the gyro-stabilized platform is connected to the positioning and orientation system through a data cable; and the control terminal is connected to the gyro-stabilized platform and the positioning and orientation system through a data cable. The present invention uniformly controls the gyro-stabilized platform and the positioning and orientation system through the control terminal, so that the remote sensing equipment operates in a stable visual axis pointing and heading and obtains the external orientation elements of the photography center of the remote sensing equipment, thereby improving the remote sensing flight efficiency, improving the remote sensing image quality and accuracy, and reducing the work intensity of the operators.

Description

Technical Field

[0001] The invention belongs to a remote sensing device, and in particular relates to a device and a method for stabilizing the posture of a remote sensing device and obtaining external orientation elements thereof. Background Art

[0002] When the remote sensing equipment is working on the aircraft, the whole system is always in motion due to the influence of airflow and fuselage. If there is no gyro-stabilized platform to provide a stable environment for the remote sensing equipment, so that the remote sensing equipment can operate in a stable line of sight and heading, the period of aerial remote sensing will be increased, which will cause difficulties for later data processing; if there is no positioning and orientation system to provide high-precision position and attitude data for the remote sensing equipment, the accuracy of aerial remote sensing will be reduced, and the difficulty of later data processing will be increased. In addition, the gyro-stabilized platform, positioning and orientation system and remote sensing equipment are three different devices that need to be operated separately. If methods cannot be taken to simplify the operation process, it will increase the difficulty of the operator's operation, resulting in a state of confusion, thus affecting the quality of the remote sensing aircraft operation. Summary of the invention

[0003] In view of the existing technical problems, the present invention proposes a device and method for stabilizing the posture of a remote sensing device and obtaining its external orientation elements, which are used to at least partially solve one of the above technical problems.

[0004] The first aspect of the present invention provides a device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements, comprising: a remote sensing aircraft, a gyro-stabilized platform, a remote sensing device, an equipment cabinet, an industrial computer, a positioning and orientation system, a GNSS antenna, an IMU, and a control terminal; the gyro-stabilized platform is fixedly connected to the downward-looking remote sensing window of the remote sensing aircraft; the remote sensing device is fixedly connected to the gyro-stabilized platform; the IMU is fixedly connected to the remote sensing device; the GNSS antenna is fixedly connected to the top of the remote sensing aircraft; the positioning and orientation system is fixedly connected to the equipment cabinet; the control terminal is fixedly connected to the equipment cabinet; The industrial computer is fixedly connected to the equipment cabinet; the equipment cabinet is fixedly connected to the floor of the remote sensing aircraft; the GNSS antenna is connected to the positioning and orientation system through a data cable; the IMU is connected to the positioning and orientation system through a data cable; the remote sensing device is connected to the industrial computer through a data cable; the remote sensing device is connected to the positioning and orientation system through a data cable; the gyro-stabilized platform is connected to the positioning and orientation system through a data cable; the control terminal is connected to the gyro-stabilized platform through a data cable; the control terminal is connected to the positioning and orientation system through a data cable;

[0005] The gyro-stabilized platform and the positioning and orientation system are used to control the attitude of the remote sensing device, wherein the stable attitude of the remote sensing device means that the remote sensing device can be controlled by the gyro-stabilized platform and the positioning and orientation system to perform remote sensing observation of the ground vertically downward from the sea level without being affected by the angular motion of the remote sensing aircraft;

[0006] The gyro-stabilized platform includes a current loop control system, a rate loop control system and a position loop control system;

[0007] Among them, the current loop generates armature current negative feedback by the current sensor; the rate loop uses the rate gyro as the rate sensor to isolate disturbances; the position loop is the main loop of the control system, using the IMU as the position sensor to enable the remote sensing load to always track the attitude of the navigation coordinate system;

[0008] The transfer function of the current loop control system is calculated and generated by the proportional parameter of the current compensator, the model function of the PWM power amplifier and the model function of the torque motor; wherein the proportional parameter of the current compensator is K ip , the model function of the PWM power amplifier is The model function of the torque motor is According to the current input I in To current output I out The closed-loop transfer function is:

[0009]

[0010] Realize current loop control, where K PWM is the gain of the PWM power amplifier, T PWM is the switching period of the PWM power amplifier, K m is the model parameter of the torque motor, armature winding transconductance, T e is the electromagnetic time constant, s is the differential operator;

[0011] The transfer function of the rate loop control system is calculated and generated by the model function of the rate compensator, the equivalent value of the current loop, the transmission ratio of the transmission mechanism and the rotational inertia of the frame; wherein the model function of the rate compensator is The equivalent value of the current loop is equivalent to the proportional link 1, and the transmission ratio of the transmission mechanism is K T , the moment of inertia of the frame is According to the rate loop open-loop transfer function:

[0012]

[0013] To achieve rate loop control, K ωp is the scaling parameter of the rate compensator, τωp is the integration time constant of the rate compensator;

[0014] The transfer function of the position loop control system is calculated and generated by the proportional parameter of the position compensator, the closed-loop transfer function of the rate loop and the integral operator; the proportional parameter of the position compensator is K θp , the closed-loop transfer function of the rate loop is The integral operator is According to the open-loop transfer function of the position loop:

[0015]

[0016] To realize the position loop control, T ω is the time constant;

[0017] The external orientation element of the remote sensing device refers to the position of the photographic center of the remote sensing device in the mapping coordinate system at the moment of exposure (X s , Y s , Z s ) and the rotation angle (φ, ω, κ) from the image space coordinate system to the image space coordinate system;

[0018] The positioning and orientation system is also used to output the WGS84 rectangular coordinates (X IMU , Y IMU , Z IMU ) and the rolling angle Φ, pitch angle Θ and yaw angle Ψ of the remote sensing aircraft.

[0019] Optionally, the gyro-stabilized platform comprises a roll frame, a pitch frame, a yaw frame, at least three torque motors, a roll rate gyro, a pitch rate gyro, a yaw rate gyro, a roll accelerometer, a pitch accelerometer, a roll rotary transformer, a pitch rotary transformer, and a yaw rotary transformer; wherein the roll frame, the pitch frame, and the yaw frame are respectively driven by at least three torque motors; the remote sensing device is mounted on the yaw frame, and its attitude change is the same as that of the yaw frame; the IMU is used to measure the attitude angle of the remote sensing device to provide an attitude reference for the gyro-stabilized platform; the roll rate gyro, the pitch rate gyro, and the yaw rate gyro are respectively used to measure the angular velocity of the roll frame, the pitch frame, and the yaw frame; the roll accelerometer and the pitch accelerometer are used to measure the horizontal attitude angle of the gyro-stabilized platform to provide an attitude reference for the gyro The stabilizing platform provides a horizontal attitude reference; the roll rotary transformer, the pitch rotary transformer and the yaw rotary transformer are respectively used to measure the relative rotation angles between the roll frame, the pitch frame and the yaw frame, and provide compensation angle information for the remote sensing equipment; when the remote sensing aircraft undergoes roll, pitch and yaw movements, the base of the gyro-stabilized platform fixed to the remote sensing aircraft applies the angular movements of roll, pitch and yaw to the roll frame, the pitch frame and the yaw frame through the bearings of the roll frame, the bearings of the pitch frame and the yaw frame, respectively; the IMU is used to measure the roll, pitch and yaw attitudes of the remote sensing load; the gyro-stabilized platform generates a control signal according to the attitude reference input and the attitude measured by the IMU to drive the at least three torque motors to generate reaction torques.

[0020] Optionally, the data cable includes a one-to-five data cable A for the positioning and orientation system, a one-to-four switching cable B between the positioning and orientation system and the gyro-stabilized platform, a gyro-stabilized platform control cable C, a data cable D for the control terminal to control the gyro-stabilized platform, a switching cable E between the positioning and orientation system and the remote sensing device, a one-to-two data cable F for the remote sensing device, a data cable G between the GNSS antenna and the positioning and orientation system, and a data cable H between the IMU and the positioning and orientation system; wherein one end a1 of the one-to-five data cable A for the positioning and orientation system is connected to the positioning and orientation system, and the other end a2 of the one-to-five data cable A for the positioning and orientation system is connected to the positioning and orientation system, and the other end a3 of the one-to-five data cable A for the positioning and orientation system is connected to the positioning and orientation system. The five ends include a first COM2 serial port a2, a first COM3 serial port a3, a first second pulse BNC interface end a4, an Ethernet port a5 and a digital input and output serial port a6; one end b1 of the one-to-four adapter cable B between the positioning and orientation system and the gyro-stabilized platform is connected to the third serial port end c1 of the gyro-stabilized platform control cable C, and the other four ends include a second COM2 serial port end b2, a second COM3 serial port end b3, a second second pulse BNC interface end b4 and an FMS serial port end b5, which are respectively connected to the first COM2 serial port end a2, the first COM3 The serial port a3, the first second pulse BNC interface end a4 and the RS-232 serial port d1 of the data cable D are connected; the control end c2 of the gyro-stabilized platform control cable C is connected to the gyro-stabilized platform; the USB end d2 of the data cable D is connected to the control terminal; the Ethernet port a5 is connected to the control terminal, the digital input and output serial port a6 is connected to the first serial port e1 of the adapter cable E between the positioning and orientation system and the remote sensing device; one end f1 of the remote sensing device one-to-two data cable F is connected to the remote sensing device, and the other two ends include The second BNC interface end f2 and the second serial port end f3 are respectively connected to the first BNC interface end e2 of the adapter cable E between the positioning and orientation system and the remote sensing equipment and the industrial computer, the first TNC interface end g1 of the data cable G between the GNSS antenna and the positioning and orientation system is connected to the positioning and orientation system, the second TNC interface end g2 is connected to the GNSS antenna, one end h1 of the data cable H between the IMU and the positioning and orientation system is connected to the positioning and orientation system, and the other end h2 of the data cable H between the IMU and the positioning and orientation system is connected to the IMU.

[0021] Optionally, the four corners of the bottom of the equipment cabinet are fixedly connected to the seat rails on the floor of the remote sensing aircraft; the equipment cabinet has three layers of aluminum plates, which are respectively fixedly connected to the industrial computer, the positioning and orientation system and the control terminal; an aluminum plate is installed on each side of the equipment cabinet, 6 circular holes are set on the first side aluminum plate, and 2 circular holes are set on the second side aluminum plate. The circular holes are used to insert, fix and isolate data cables between devices, and the distance between adjacent circular holes is twice the diameter of the circular holes.

[0022] The six round holes on the first side aluminum plate correspond to the following data cables:

[0023] The cable connecting the Ethernet port a5 and the control terminal;

[0024] A cable connecting the first pulse-per-second BNC interface end a4 and the second pulse-per-second BNC interface end b4;

[0025] A cable connecting the first COM3 serial port a3 and the COM3 serial port b3;

[0026] A cable connecting the first COM2 serial port a2 and the second COM2 serial port b2;

[0027] The digital input and output serial port a6 is connected to the first serial port e1, and the first BNC interface terminal e2 is connected to the second BNC interface terminal f2 by a cable;

[0028] The connection between the second serial port f3 and the industrial computer;

[0029] The two round holes on the second side aluminum plate correspond to the following data cables:

[0030] Data cable G between the GNSS antenna and the positioning and orientation system, and data cable H between the IMU and the positioning and orientation system.

[0031] Optionally, the remote sensing equipment, the gyro-stabilized platform, the industrial computer, the positioning and orientation system and the control terminal are all equipped with grounding devices to prevent static electricity from damaging the equipment; the grounding device includes: a screw, a nut, a plurality of nuts, a stainless steel support belt, and a grounding lead, the nut is installed on the upper part of the screw, the plurality of nuts are installed in the middle part of the screw, one end of the grounding lead is fixed between the plurality of nuts and contacts the screw, the screw is fixed on the industrial computer, the positioning and orientation system and the control terminal, and the other end of the grounding lead is fixed on the ground rail; annular sleeves are provided at both ends of the stainless steel support belt, wherein one end of the annular sleeve is fixed to the bottom of the nut, and the other end of the annular sleeve is fixed to the lower part of the screw.

[0032] The second aspect of the present invention provides a control method for the above-mentioned stable remote sensing device attitude and the device for obtaining its external orientation elements, wherein the control terminal is installed with a Windows operating system, and the gyro-stabilized platform control software is installed in the Windows operating system, characterized in that the method for the gyro-stabilized platform control software to control the gyro-stabilized platform includes: using the control terminal to control the data cable D of the gyro-stabilized platform to connect the control terminal and the gyro-stabilized platform, wherein the USB terminal d2 is connected to the control terminal, the RS-232 serial port terminal d1 is connected to the FMS serial port terminal b5, the FMS serial port terminal b5 is connected to the third serial port terminal c1, and the control terminal c2 is connected to the gyro-stabilized platform. Open the computer management program of the control terminal and click "Device Manager". Click "Port: COM and LPT". Find the USB to serial communication port COMn, where n=1, 2, 3... Open the gyro-stabilized platform control software and click "Communication Settings". In the communication settings, select the COM port as the USB to serial communication port COMn. Click "Function Settings". In the function setting, set the angle parameters, wherein the range of the roll angle is: -7°~+7°; the range of the pitch angle is: -8°~+6°; the range of the yaw angle is: -30°~+30°. In the function setting, select the type of remote sensing equipment. In the function setting, input the vertical offset of the pitch angle, wherein the vertical offset of the pitch angle is equal to the angle between the plane where the gyro-stabilized platform is located and the sea level during the flight. After completing the setting, enter the platform state. When the remote sensing aircraft is about to enter the flight route, click "Open stable platform", the gyro-stabilized platform enters the adaptive control state and controls the remote sensing equipment to shoot vertically; at this time, the gyro-stabilized platform continuously sends gyro-encoded data to the positioning and orientation system through the second COM3 serial port end b3 and the second pulse BNC interface end b4; when the remote sensing aircraft completes the route, click "Close stable platform", the gyro-stabilized platform returns to the original state and stops controlling the remote sensing equipment. After completing all routes according to the above method, close the gyro-stabilized platform control software.

[0033] The third aspect of the present invention provides a control method for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements. The control terminal is installed with a Windows operating system, and the positioning and orientation system control software is installed in the Windows operating system. It is characterized in that the method for the positioning and orientation system control software to control the positioning and orientation system includes: using the one-to-five data cable A of the positioning and orientation system to connect the control terminal with the positioning and orientation system, wherein the Ethernet port a5 is connected to the control terminal. Open the network and sharing center of the control terminal, click the local connection, click properties, double-click Internet Protocol version 4: TCP / IPv4, set the IP address to 129.100.0.25, and set the subnet mask to 255.255.0.0. Open the positioning and orientation system control software, enter the setting interface, set the IP address of the positioning and orientation system to 129.100.0.100, and set the subnet mask to 255.255.0.0. Set the IMU eccentricity component, GNSS eccentricity component and IMU placement angle. Set the RMS accuracy: attitude angle accuracy is 0.008-0.05 degrees, absolute azimuth accuracy is 0.008-0.05 degrees, position accuracy is 0.5-2 meters, and velocity accuracy is 0.05-0.5 meters / second. Set the Event trigger rule: select positive edge trigger. Set the COM port: COM1 transmits GNSS data, the baud rate is 9600, and the frequency is 1Hz. The information receiver in COM2 selects the PAST1 format, the baud rate is 38400, and the frequency is 20Hz; the information receiver in COM3 selects the P30_GIM Encoder Input format, the baud rate is 38400, and the frequency is 1Hz. Set the data recording parameters: select the type of data to be recorded, and set the recording frequency to 50Hz. After completing the settings, when the remote sensing aircraft takes off, turn on the positioning and orientation system, and observe the navigation mode, IMU status, GNSS receiver status, gyro-stabilized platform status, memory card status, memory card available space and other information of the system in the control software. If the navigation mode is in the calibration mode, the IMU status is normal, the GNSS receiver status is normal, the gyro-stabilized platform status is normal, the memory card is in the idle state, and the memory card available space is greater than 50%, the system can be judged to be normal; at this time, the positioning and orientation system continuously sends angle element data to the gyro-stabilized platform through the COM2 serial port. Observe the information of attitude angle accuracy, absolute azimuth accuracy, position accuracy and speed accuracy. If they all meet the accuracy set above, the system accuracy can be judged to be normal; start recording data, and the positioning and orientation system starts to obtain the external orientation elements of the remote sensing equipment. After flying all routes, stop recording data and close the positioning and orientation system control software during the aircraft's return process.The relationship between the gyro-stabilized platform and the positioning and orientation system is: the positioning and orientation system sends angular element data such as roll angle, pitch angle and yaw angle to the gyro-stabilized platform through the COM2 serial port, which is used to correct the angular error of the gyro-stabilized platform; the gyro-stabilized platform sends gyro encoding data to the positioning and orientation system through the COM3 serial port and the pulse-per-second BNC interface, which is used to calculate the dynamic eccentricity component of the GNSS antenna and IMU. There is no need to forcibly install the GNSS antenna within 10 cm from the photographic center of the remote sensing equipment, which provides a variety of options for the installation of the GNSS antenna.

[0034] A fourth aspect of the present invention provides a method for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements, characterized in that the positioning and orientation system outputs the WGS84 rectangular coordinates (X IMU , Y IMU , Z IMU ) and the aircraft's roll angle Φ, pitch angle Θ and yaw angle Ψ include:

[0035] According to the following formula:

[0036]

[0037] Solve for the exterior azimuth elements (φ, ω, κ); where, is the rotation matrix from the image coordinate system m to the geocentric coordinate system E, is the rotation matrix from the geocentric coordinate system E to the local geographic coordinate system g, is the rotation matrix from the local geographic coordinate system g to the IMU coordinate system b, is the rotation matrix from the IMU coordinate system b to the remote sensing device coordinate system c, It is the rotation matrix from the remote sensing device coordinate system c to the image space coordinate system i; where the origin of the image space coordinate system i is located at the image principal point, the x-axis points to the flight direction, the y-axis points to the left side of the image, and the z-axis points upward; the origin of the remote sensing device coordinate system c is located at the photography center, the x-axis points to the flight direction, the y-axis points to the right side of the remote sensing device, and the z-axis points downward; the origin of the IMU coordinate system b is located at the IMU gyroscope center, the x-axis points to the flight direction, the y-axis points to the right side of the aircraft, and the z-axis points downward; the local geographic coordinate system g is tangent to the reference ellipsoid, the x-axis points to the north, the y-axis points to the east, and the z-axis points downward; the origin of the geocentric coordinate system E is at the center of the reference ellipsoid, the x-axis points to the intersection of the equator and the Greenwich meridian, the y-axis points to the intersection of the equator and the 90° meridian, and the z-axis points to the North Pole; the mapping coordinate system m is an arbitrary local right-handed coordinate system specified by the user.

[0038] According to the following formula:

[0039]

[0040] Solve for the exterior orientation line element (Xs , Y s , Z s ), where (x l ,y l , z l ) is the eccentric component of the photographic center of the remote sensing equipment in the IMU coordinate system and is a known value.

[0041] Due to the adoption of the above technical solution, the advantages of the present invention are:

[0042] 1. The present invention controls the gyro-stabilized platform and the positioning and orientation system simultaneously through the control terminal during the flight, thereby simplifying the operation process. Instead of separately operating three different devices, namely the gyro-stabilized platform, the positioning and orientation system and the remote sensing device, it becomes separately operating two different devices, namely the control terminal and the remote sensing device, thereby reducing the difficulty of the operation of the operator and avoiding a chaotic situation, thereby ensuring the quality of the operation on the remote sensing aircraft.

[0043] 2. The present invention enables remote sensing equipment to operate in a stable line of sight pointing and heading, while obtaining the external orientation elements of the photographic center of the remote sensing equipment, thereby improving the efficiency of aerial remote sensing, improving the quality and accuracy of remote sensing data, and reducing the workload of early and late stage operators.

[0044] 3. The present invention provides circular holes on the equipment cabinet for inserting, fixing and isolating data cables between devices, thereby ensuring that the data cables will not stick together and preventing the data cables from interfering with each other.

[0045] 4. The equipment of the present invention is equipped with a grounding device to prevent static electricity from causing damage to the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram showing a connection structure of a device for stabilizing the posture of a remote sensing device and acquiring its external orientation elements according to an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the structure of a grounding device according to the present invention is shown;

[0048] Figure 3 The data processing flow chart according to an embodiment of the present invention is schematically shown.

[0049] [Reference Signs]

[0050] 1-screw, 2-nut, 3-several nuts, 4-stainless steel support belt, 5-grounding lead, 6-equipment cabinet, 7-remote sensing equipment;

[0051] A- One-to-five data cable of the positioning and orientation system, B- One-to-four switching cable between the positioning and orientation system and the gyro-stabilized platform, C- Control cable of the gyro-stabilized platform, D- Data cable of the control terminal controlling the gyro-stabilized platform, E- Switching cable between the positioning and orientation system and the remote sensing equipment, F- One-to-two data cable of the remote sensing equipment, G- Data cable between the GNSS antenna and the positioning and orientation system, H- Data cable between the IMU and the positioning and orientation system;

[0052] a1-one end of the one-to-five data cable A of the positioning and orientation system, a2-the first COM2 serial port, a3-the first COM3 serial port, a4-the first second pulse BNC interface, a5-the Ethernet port, a6-the digital input and output serial port; b1-one end of the one-to-four conversion cable B between the positioning and orientation system and the gyro-stabilized platform, b2-the second COM2 serial port, b3-the second COM3 serial port, b4-the second second pulse BNC interface, b5-the FMS serial port, c 1-first serial port, c2-control end, d1-RS-232 serial port; d2-USB end, e1-first serial port, e2-first BNC interface end, f1-one end of the remote sensing equipment one-to-two data cable F, f2-second BNC interface end, f3-second serial port, g1-first TNC interface end, g2-second TNC interface end, h1-one end of the data cable H between the IMU and the positioning and orientation system, h2-the other end of the data cable H between the IMU and the positioning and orientation system. DETAILED DESCRIPTION

[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0054] The embodiment of the present invention provides a device for stabilizing the remote sensing device posture and obtaining its external orientation elements, see Figure 1The device includes a remote sensing aircraft, a gyro-stabilized platform, remote sensing equipment, an equipment cabinet, an industrial computer, a positioning and orientation system, a GNSS antenna, an IMU, and a control terminal (for example, a desktop computer, a laptop computer, etc.). Among them, the gyro-stabilized platform is fixedly connected to the downward remote sensing window of the remote sensing aircraft, the remote sensing equipment is fixedly connected to the gyro-stabilized platform, and the IMU is fixedly connected to the remote sensing equipment; the GNSS antenna is fixedly connected to the top of the remote sensing aircraft, the positioning and orientation system is fixedly connected to the equipment cabinet, the control terminal is fixedly connected to the equipment cabinet, the industrial computer is fixedly connected to the equipment cabinet, the equipment cabinet is fixedly connected to the aircraft floor, the GNSS antenna is connected to the positioning and orientation system through a data cable, the IMU is connected to the positioning and orientation system through a data cable, the remote sensing equipment is connected to the industrial computer through a data cable, the remote sensing equipment is connected to the positioning and orientation system through a data cable, the gyro-stabilized platform is connected to the positioning and orientation system through a data cable, the control terminal is connected to the gyro-stabilized platform through a data cable, and the control terminal is connected to the positioning and orientation system through a data cable.

[0055] The gyro-stabilized platform and the positioning and orientation system are used to control the attitude of the remote sensing equipment, wherein stabilizing the attitude of the remote sensing equipment means that the remote sensing equipment can perform ground remote sensing observation vertically downward from the sea level through the gyro-stabilized platform and the positioning and orientation system without being affected by the angular motion of the aircraft.

[0056] The gyro-stabilized platform includes a current loop control system, a rate loop control system and a position loop control system.

[0057] Among them, the current loop generates armature current negative feedback from the current sensor to reduce the impact of power supply voltage fluctuations, improve the linearity of the control torque, and achieve smooth control of the current without sudden changes. The rate loop uses the rate gyro as the rate sensor to isolate disturbances, ensure the rapidity of system response, and maintain the stability of the load inertial space. The position loop is the main loop of the control system, using the IMU as the position sensor to ensure that the remote sensing load always tracks the attitude of the navigation coordinate system.

[0058] The transfer function of the current loop control system is calculated and generated by the proportional parameter of the current compensator, the model function of the PWM power amplifier and the model function of the torque motor. i , the model function of the PWM power amplifier is The model function of the torque motor is According to the current input I in To current output I out The closed-loop transfer function is:

[0059]

[0060] Realize current loop control, where K PWMis the gain of the PWM power amplifier, T PWM is the switching period of the PWM power amplifier, K m is the model parameter of the torque motor, armature winding transconductance, T e is the electromagnetic time constant and s is the differential operator.

[0061] The transfer function of the rate loop control system is calculated and generated by the model function of the rate compensator, the equivalent value of the current loop, the transmission ratio of the transmission mechanism and the moment of inertia of the frame; the model function of the rate compensator is The equivalent value of the current loop is equivalent to the proportional link 1, and the transmission ratio of the transmission mechanism is K T , the moment of inertia of the frame is According to the rate loop open-loop transfer function:

[0062]

[0063] To achieve rate loop control, K ωp is the scaling parameter of the rate compensator, τ ωp is the integration time constant of the rate compensator.

[0064] The transfer function of the position loop control system is calculated by the proportional parameter of the position compensator, the closed-loop transfer function of the rate loop and the integral operator. θp , the closed-loop transfer function of the rate loop is The integral operator is According to the open-loop transfer function of the position loop:

[0065]

[0066] To realize the position loop control, T ω is the time constant. ;

[0067] The external orientation element of the remote sensing device refers to the position of the photographic center of the remote sensing device in the mapping coordinate system at the moment of exposure (X s , Y s , Z s ) and the rotation angle (φ, ω, κ) from the image space coordinate system to the image space coordinate system;

[0068] The positioning and orientation system can output the WGS84 rectangular coordinates (X IMU , Y IMU , Z IMU ) and the aircraft’s roll angle Φ, pitch angle Θ and yaw angle Ψ.

[0069] In one embodiment of the present invention, the gyro-stabilized platform may include a roll frame, a pitch frame, a yaw frame, at least three torque motors, a roll rate gyro, a pitch rate gyro, a yaw rate gyro, a roll accelerometer, a pitch accelerometer, a roll rotary transformer, a pitch rotary transformer and a yaw rotary transformer. Among them, the roll frame, the pitch frame and the yaw frame are driven by at least three torque motors respectively. The remote sensing device is installed on the yaw frame and its attitude changes are the same as the yaw frame. The IMU is used to measure the attitude angle of the remote sensing device and provide an attitude reference for the gyro-stabilized platform. The roll rate gyro, the pitch rate gyro and the yaw rate gyro are used to measure the angular velocity of the roll frame, the pitch frame and the yaw frame respectively. The roll accelerometer and the pitch accelerometer are used to measure the horizontal attitude angle of the gyro-stabilized platform and provide a horizontal attitude reference for the gyro-stabilized platform. The roll rotary transformer, pitch rotary transformer and yaw rotary transformer are used to measure the relative rotation angles between the roll frame, pitch frame and yaw frame respectively, providing compensation angle information for remote sensing equipment.

[0070] When the remote sensing aircraft undergoes roll, pitch and yaw movements, the gyro-stabilized platform base fixed to the aircraft transfers the angular motions of roll, pitch and yaw to the roll frame, pitch frame and yaw frame through the roll frame bearing, pitch frame bearing and yaw frame bearing respectively, and the IMU measures the roll, pitch and yaw attitudes of the remote sensing payload. The gyro-stabilized platform generates control signals based on the attitude reference input and the attitude measured by the IMU to drive the three torque motors to generate reaction torque, thereby maintaining the stability of the remote sensing payload attitude.

[0071] In one embodiment of the present invention, there are 8 types of data cables in total, forming wiring routes that do not interfere with each other. The 8 types of data cables may include a one-to-five data cable A for the positioning and orientation system, a one-to-four switching cable B between the positioning and orientation system and the gyro-stabilized platform, a gyro-stabilized platform control cable C, a data cable D for the control terminal to control the gyro-stabilized platform, a switching cable E between the positioning and orientation system and the remote sensing device, a one-to-two data cable F for the remote sensing device, a data cable G between the GNSS antenna and the positioning and orientation system, and a data cable H between the IMU and the positioning and orientation system.

[0072] Among them, one end a1 of the one-to-five data cable A of the positioning and orientation system is connected to the positioning and orientation system, and the other five ends include the first COM2 serial port a2, the first COM3 serial port a3, the first second pulse BNC interface port a4, the Ethernet port a5 and the digital input and output serial port a6.

[0073] One end b1 of the one-to-four adapter cable B between the positioning and orientation system and the gyro-stabilized platform is connected to the third serial port c1 of the gyro-stabilized platform control cable C, and the other four ends include the second COM2 serial port b2, the second COM3 serial port b3, the second pulse BNC interface end b4 and the FMS serial port b5, which are respectively connected to the first COM2 serial port a2, the first COM3 serial port a3, the first second pulse BNC interface end a4 and the RS-232 serial port d1 of the data cable D. The control end c2 of the gyro-stabilized platform control cable C is connected to the gyro-stabilized platform. The USB end d2 of the data cable D is connected to the control terminal; the Ethernet port end a5 of the one-to-five data cable A of the positioning and orientation system is connected to the control terminal, and the digital input and output serial port end a6 is connected to the first serial port end e1 of the adapter cable E between the positioning and orientation system and the remote sensing device; one end f1 of the one-to-two data cable F of the remote sensing device is connected to the remote sensing device, and the other two ends include a second BNC interface end f2 and a second serial port end f3, which are respectively connected to the first BNC interface end e2 of the adapter cable E between the positioning and orientation system and the remote sensing device and the industrial computer, the first TNC interface end g1 of the data cable G between the GNSS antenna and the positioning and orientation system is connected to the positioning and orientation system, and the second TNC interface end g2 is connected to the GNSS antenna, one end h1 of the data cable H between the IMU and the positioning and orientation system is connected to the positioning and orientation system, and the other end h2 of the data cable H between the IMU and the positioning and orientation system is connected to the IMU.

[0074] In one embodiment of the present invention, the four corners of the bottom of the equipment cabinet are fixedly connected to the seat rails on the floor of the remote sensing aircraft. The equipment cabinet has three layers of aluminum plates, which are respectively fixedly connected to the industrial computer, the positioning and orientation system, and the control terminal from bottom to top. An aluminum plate is installed on each side of the equipment cabinet. The first aluminum plate (the left aluminum plate) is provided with 6 circular holes, and the second aluminum plate (the right aluminum plate) is provided with 2 circular holes. The circular holes are used to insert, fix and isolate data cables between devices. The distance between adjacent circular holes is twice the diameter of the circular holes.

[0075] Among them, the data cables corresponding to the 6 round holes on the left aluminum plate are: the cable connecting the Ethernet port a5 and the control terminal; the cable connecting the first second pulse BNC interface a4 and the second second pulse BNC interface b4; the cable connecting the first COM3 serial port a3 and the COM3 serial port b3; the cable connecting the first COM2 serial port a2 and the second COM2 serial port b2; the cable connecting the digital input and output serial port a6 and the first serial port e1, the first BNC interface e2 and the second BNC interface f2; the cable connecting the second serial port f3 and the industrial computer. The data cables corresponding to the 2 round holes on the second side aluminum plate are: the data cable G between the GNSS antenna and the positioning and orientation system, and the data cable H between the IMU and the positioning and orientation system. The arrangement of the round holes can ensure that the data cables will not stick together and prevent the data cables from interfering with each other.

[0076] In one embodiment of the present invention, the remote sensing equipment, gyro-stabilized platform, industrial computer, positioning and orientation system and control terminal are all equipped with grounding devices to prevent static electricity from damaging the equipment. Figure 2 As shown, the grounding device may include, for example, a screw 1, a nut 2, a plurality of nuts 3, a stainless steel support belt 4, and a grounding lead 5. The nut 2 is mounted on the upper part of the screw 1, and the plurality of nuts 3 are mounted in the middle part of the screw 1. One end of the grounding lead 5 is fixed between the plurality of nuts 3 and in contact with the screw 1. The screw 1 is fixed on the industrial computer, the positioning and orientation system, and the control terminal. The other end of the grounding lead 5 is fixed on the ground rail. The stainless steel support 4 is provided with an annular sleeve at both ends, wherein the upper annular sleeve is fixed on the bottom of the nut 2, and the lower annular sleeve is fixed on the lower part of the screw 1. When installing or removing, the stainless steel support belt 4 can prevent the plurality of nuts 3 from falling off, and the nut 2 can be conveniently installed or removed by hand.

[0077] In view of the apparatus for stabilizing the remote sensing device attitude and obtaining its external orientation elements provided in the above embodiment, the embodiment of the present invention further provides a control method for controlling a gyro-stabilized platform. The control terminal is installed with a Windows operating system, and the gyro-stabilized platform control software is installed in the Windows operating system. Figure 3 As shown, the control method may include: 1) connecting the control terminal and the gyro-stabilized platform using a data cable D. Specifically, the USB end d2 of the data cable D is connected to the control terminal, the RS-232 serial port end d1 of the data cable D is connected to the FMS serial port end b5 of the adapter cable B, the FMS serial port end b5 of the adapter cable B is connected to the third serial port end c1 of the control cable C, and the control end c2 of the control cable C is connected to the gyro-stabilized platform.

[0078] 2) Open the control terminal computer management program and click "Device Manager".

[0079] 3) Click "Ports: COM and LPT".

[0080] 4) Find the USB to serial communication port: COMn, n=1, 2, 3...

[0081] 5) Open the gyro-stabilized platform control software and click "Communication Settings".

[0082] 6) In the communication settings, select the COM port as COMn in step 4.

[0083] 7) Click “Function Settings”.

[0084] 8) In the function settings, set the angle parameters, where the roll angle range is: -7°-+7°; the pitch angle range is: -8°-+6°; the yaw angle range is: -30°-+30°.

[0085] 9) In the function settings, select the type of remote sensing equipment.

[0086] 10) In the function settings, enter the vertical offset of the pitch angle. The vertical offset of the pitch angle is equal to the angle between the plane where the gyro stabilized platform is located and the sea level during flight.

[0087] 11) After completing the settings, enter the platform state. When the remote sensing aircraft is about to enter the flight route, click "Open stable platform", the gyro stabilized platform enters the adaptive control state and controls the remote sensing equipment to shoot vertically. At this time, the gyro stabilized platform continues to send gyro coded data to the positioning and orientation system through the COM3 serial port and the pulse per second BNC interface; when the remote sensing aircraft completes the flight route, click "Close stable platform", the gyro stabilized platform returns to the original state and stops controlling the remote sensing equipment.

[0088] 12) After completing all routes according to step 11, close the gyro-stabilized platform control software.

[0089] In view of the apparatus for stabilizing the remote sensing device posture and obtaining its external orientation elements provided in the above embodiment, the embodiment of the present invention also provides a control method for controlling the positioning and orientation system. The control terminal is installed with the Windows operating system, and the positioning and orientation system control software is installed in the Windows operating system. Figure 3 As shown, the control method may include:

[0090] 1) Use data cable A to connect the control terminal to the positioning and orientation system: the Ethernet port a5 of data cable A is connected to the control terminal.

[0091] 2) Open the Network and Sharing Center of the control terminal, click Local Area Connection, click Properties, double-click Internet Protocol Version 4: TCP / IPv4, set the IP address to 129.100.0.25, and the subnet mask to 255.255.0.0.

[0092] 3) Open the positioning and orientation system control software, enter the setting interface, set the IP address of the positioning and orientation system to 129.100.0.100, and the subnet mask to 255.255.0.0.

[0093] 4) Set the IMU eccentricity component, GNSS eccentricity component and IMU installation angle.

[0094] 5) Set the RMS accuracy: attitude angle accuracy is 0.008-0.05 degrees, absolute azimuth accuracy is 0.008-0.05 degrees, position accuracy is 0.5-2 meters, and velocity accuracy is 0.05-0.5 meters per second.

[0095] 6) Set the Event trigger rule: Select Positive Edge Trigger.

[0096] 7) Set the COM port: COM1 transmits GNSS data with a baud rate of 9600 and a frequency of 1Hz; the information receiver in COM2 selects the PAST1 format with a baud rate of 38400 and a frequency of 20Hz; the information receiver in COM3 selects the P30_GIMEncoder Input format with a baud rate of 38400 and a frequency of 1Hz.

[0097] Among them, PAST1 is a 32-byte message, which contains the time, position, attitude, speed and trajectory of the reference coordinate system.

[0098] Among them, P30_GIM Encoder Input consists of gyroscope encoder angle data (Tx, Ty, Tz), which is used to define the coordinate system transformation between the aircraft and the ground. The gyroscope provides encoded data to the positioning and orientation system for calculating the dynamic eccentricity component of the GNSS antenna and IMU.

[0099] 8) Set data recording parameters: Select the type of data to be recorded and set the recording frequency to 50Hz.

[0100] 9) After completing the settings, when the remote sensing aircraft takes off, turn on the positioning and orientation system, and observe the system's navigation mode, IMU status, GNSS receiver status, gyro-stabilized platform status, memory card status, memory card available space and other information in the control software. If the navigation mode is in calibration mode, the IMU status is normal, the GNSS receiver status is normal, the gyro-stabilized platform status is normal, the memory card is in idle state, and the memory card available space is greater than 50%, then the system can be determined to be normal; at this time, the positioning and orientation system continuously sends angular element data to the gyro-stabilized platform through the COM2 serial port.

[0101] 10) Observe the information of attitude angle accuracy, absolute azimuth accuracy, position accuracy and velocity accuracy. If they all meet the accuracy of step 5) above, it can be determined that the system accuracy is normal.

[0102] 11) Start recording data. At this time, the positioning and orientation system begins to obtain the external orientation elements of the remote sensing equipment. After all routes are flown, stop recording data during the aircraft's return process and turn off the positioning and orientation system control software.

[0103] Among them, the relationship between the gyro-stabilized platform and the positioning and orientation system is: the positioning and orientation system sends angular element data such as roll angle, pitch angle and yaw angle to the gyro-stabilized platform through the COM2 serial port to correct the angular error of the gyro-stabilized platform. The gyro-stabilized platform sends gyro encoding data to the positioning and orientation system through the COM3 serial port and the second pulse BNC interface to calculate the dynamic eccentricity component of the GNSS antenna and IMU. There is no need to forcibly install the GNSS antenna within 10 cm from the photographic center of the remote sensing equipment, which provides a variety of options for the installation of the GNSS antenna.

[0104] The embodiment of the present invention also provides a method for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements, wherein the positioning and orientation system outputs the WGS84 rectangular coordinates (X IMU , Y IMU , Z IMU ) and the aircraft's roll angle Φ, pitch angle Θ and yaw angle Ψ include:

[0105] According to the following formula:

[0106]

[0107] Solve for the exterior azimuth elements (φ, ω, κ). Among them, is the rotation matrix from the image coordinate system m to the geocentric coordinate system E, is the rotation matrix from the geocentric coordinate system E to the local geographic coordinate system g, is the rotation matrix from the local geographic coordinate system g to the IMU coordinate system b, is the rotation matrix from the IMU coordinate system b to the remote sensing device coordinate system c, It is the rotation matrix from the remote sensing device coordinate system c to the image space coordinate system i.

[0108] Among them, the origin of the image space coordinate system i is located at the image principal point, the x-axis points to the flight direction, the y-axis points to the left side of the image, and the z-axis points upward.

[0109] The origin of the remote sensing device coordinate system c is located at the photography center, the x-axis points to the flight direction, the y-axis points to the right side of the remote sensing device, and the z-axis points downward.

[0110] The origin of the IMU coordinate system b is located at the center of the IMU gyroscope, the x-axis points in the direction of flight, the y-axis points to the right of the aircraft, and the z-axis points downward.

[0111] The local geographic coordinate system g is tangent to the reference ellipsoid, with the x-axis pointing north, the y-axis pointing east, and the z-axis pointing downward.

[0112] The origin of the geocentric coordinate system E is at the center of the reference ellipsoid, the x-axis points to the intersection of the equator and the Greenwich meridian, the y-axis points to the intersection of the equator and the 90° meridian, and the z-axis points to the North Pole;

[0113] The drawing coordinate system m is an arbitrary local right-handed coordinate system specified by the user.

[0114] According to the following formula:

[0115]

[0116] Solve for the exterior orientation line element (X s , Y s , Z s ), where (x l ,y l , z l ) is the eccentric component of the photographic center of the remote sensing equipment in the IMU coordinate system and is a known value.

[0117] So far, six external orientation elements of the remote sensing equipment have been obtained, namely three line elements (X s , Y s , Z s ) and 3 angular elements (φ, ω, κ).

[0118] The present invention realizes functions such as linkage of remote sensing equipment, remote sensing data transmission and real-time processing of remote sensing data through computer remote control. Multiple remote sensing devices at different positions can be controlled at a fixed seat on the aircraft, thus avoiding the danger of walking back and forth in the air, ensuring the safety of the operator, saving time for backing up and processing data, being able to quickly complete remote sensing tasks and improving the efficiency of aviation remote sensing.

[0119] The device and method provided by the embodiment of the present invention can complete the remote sensing monitoring task faster and more stably than the traditional manned aerial remote sensing, and can obtain at least two results: 1) multi-source remote sensing data; 2) real-time processed remote sensing data results. Therefore, the working efficiency of the device is improved.

[0120] In one embodiment of the present invention, the remote sensing equipment includes equipment with different functions such as high-resolution linear array digital aerial cameras, high-resolution area array digital aerial cameras, multi-modal digital aerial cameras, push-broom hyperspectral imagers, three-dimensional laser radars, etc.

[0121] The gyro-stabilized platform, also known as the gyro platform or inertial platform, is a device that uses the characteristics of a gyroscope to maintain the stability of the platform's orientation.

[0122] The Positioning & Orientation System (POS) integrates DGPS (DifferentialGPS) technology and Inertial Navigation System (INS) technology. It can obtain the spatial position and three-axis attitude information of moving objects and is widely used in the navigation and positioning of aircraft, ships and missiles.

[0123] IMU is a device that measures the three-axis attitude angle and acceleration of an object. Generally, IMU includes a three-axis gyroscope and a three-axis accelerometer. Some 9-axis IMUs also include a three-axis magnetometer.

[0124] The full name of GNSS is Global Navigation Satellite System, which refers to all satellite navigation systems, including global, regional and enhanced, such as the United States' GPS, Russia's Glonass, Europe's Galileo, China's BeiDou Satellite Navigation System, and related enhancement systems, such as the United States' WAAS (Wide Area Augmentation System), Europe's EGNOS (European Geostationary Navigation Overlay System) and Japan's MSAS (Multifunctional Transport Satellite Augmentation System), etc., and also covers other satellite navigation systems under construction and to be built in the future.

[0125] PWM refers to pulse width modulation. Pulse width modulation is an analog control method that modulates the bias of the transistor base or MOS tube gate according to the change of the corresponding load to achieve the change of the transistor or MOS tube conduction time, thereby achieving the change of the output of the switching regulated power supply.

[0126] TNC is an antenna interface.

[0127] BNC is a connector for coaxial cable.

[0128] FMS is the abbreviation of Flight Management System.

[0129] RS-232 is one of the commonly used serial communication interface standards. It was jointly developed by the American Electronics Industries Association (EIA), Bell System, modem manufacturers and computer terminal manufacturers in 1970. Its full name is "Technical Standard for Serial Binary Data Exchange Interface between Data Terminal Equipment (DTE) and Data Communications Equipment (DCE)".

[0130] COM is a serial communication port, also known as serial port.

[0131] LPT is a line print terminal, which is used to connect to the parallel communication port of a printer or scanner.

[0132] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements, characterized in that: include: Remote sensing aircraft, gyro-stabilized platform, remote sensing equipment, equipment cabinet, industrial computer, positioning and orientation system, GNSS antenna, IMU, control terminal; The gyro-stabilized platform is fixedly connected to the downward-looking remote sensing window of the remote sensing aircraft; the remote sensing equipment is fixedly connected to the gyro-stabilized platform; the IMU is fixedly connected to the remote sensing equipment; the GNSS antenna is fixedly connected to the top of the remote sensing aircraft; the positioning and orientation system is fixedly connected to the equipment cabinet; and the control terminal is fixedly connected to the equipment cabinet; The industrial computer is fixedly connected to the equipment cabinet; The equipment cabinet is fixedly connected to the floor of the remote sensing aircraft; the GNSS antenna is connected to the positioning and orientation system through a data cable; the IMU is connected to the positioning and orientation system through a data cable; the remote sensing equipment is connected to the industrial computer through a data cable; the remote sensing equipment is connected to the positioning and orientation system through a data cable; the gyro-stabilized platform is connected to the positioning and orientation system through a data cable; the control terminal is connected to the gyro-stabilized platform through a data cable; the control terminal is connected to the positioning and orientation system through a data cable; The gyro-stabilized platform and the positioning and orientation system are used to control the attitude of the remote sensing device, wherein the stable attitude of the remote sensing device means that the remote sensing device can be controlled by the gyro-stabilized platform and the positioning and orientation system to perform remote sensing observation of the ground vertically downward from the sea level without being affected by the angular motion of the remote sensing aircraft; The gyro-stabilized platform includes a current loop control system, a rate loop control system and a position loop control system; Among them, the current loop generates armature current negative feedback by the current sensor; the rate loop uses the rate gyro as the rate sensor to isolate disturbances; the position loop is the main loop of the control system, using the IMU as the position sensor to enable the remote sensing load to always track the attitude of the navigation coordinate system; The transfer function of the current loop control system is calculated and generated by the proportional parameter of the current compensator, the model function of the PWM power amplifier and the model function of the torque motor; wherein the proportional parameter of the current compensator is , the model function of the PWM power amplifier is , the model function of the torque motor is , according to the current input To current output The closed-loop transfer function is: Implement current loop control, where is the gain of the PWM power amplifier, is the switching period of the PWM power amplifier, is the armature winding transconductance of the torque motor model parameter, is the electromagnetic time constant, is a differential operator; The transfer function of the rate loop control system is calculated and generated by the model function of the rate compensator, the equivalent value of the current loop, the transmission ratio of the transmission mechanism and the rotational inertia of the frame; wherein the model function of the rate compensator is , the equivalent value of the current loop is equivalent to the proportional link 1, and the transmission ratio of the transmission mechanism is , the moment of inertia of the frame is , according to the rate loop open-loop transfer function: Implement rate loop control, where is the scaling parameter of the rate compensator, is the integration time constant of the rate compensator; The transfer function of the position loop control system is calculated and generated by the proportional parameter of the position compensator, the closed-loop transfer function of the rate loop and the integral operator; the proportional parameter of the position compensator is , the closed-loop transfer function of the rate loop is , the integral operator is , according to the open-loop transfer function of the position loop: Implement position loop control, where is the time constant; The external orientation element of the remote sensing device refers to the position of the photographic center of the remote sensing device in the mapping coordinate system at the moment of exposure. and the rotation angle from the image coordinate system to the image space coordinate system ; The positioning and orientation system is also used to output the WGS84 rectangular coordinates of the IMU origin and the rolling angle of the remote sensing aircraft , Pitch angle and declination ; The gyro-stabilized platform comprises a roll frame, a pitch frame, a yaw frame, at least three torque motors, a roll rate gyro, a pitch rate gyro, a yaw rate gyro, a roll accelerometer, a pitch accelerometer, a roll rotary transformer, a pitch rotary transformer, and a yaw rotary transformer; Wherein, the roll frame, the pitch frame and the yaw frame are driven by at least three torque motors; the remote sensing device is installed on the yaw frame, and its attitude change is the same as that of the yaw frame; the IMU is used to measure the attitude angle of the remote sensing device and provide an attitude reference for the gyro-stabilized platform; the roll rate gyro, the pitch rate gyro and the yaw rate gyro are used to measure the angular velocity of the roll frame, the pitch frame and the yaw frame respectively; the roll accelerometer and the pitch accelerometer are used to measure the horizontal attitude angle of the gyro-stabilized platform and provide a horizontal attitude reference for the gyro-stabilized platform; the roll rotary transformer, the pitch rotary transformer and the yaw rotary transformer are used to measure the relative rotation angle between the roll frame, the pitch frame and the yaw frame respectively, and provide compensation angle information for the remote sensing device; When the remote sensing aircraft undergoes rolling, pitching and yawing movements, the base of the gyro-stabilized platform fixedly connected to the remote sensing aircraft applies the angular movements of rolling, pitching and yawing to the roll frame, the pitch frame and the yaw frame through the bearings of the roll frame, the pitch frame and the yaw frame, respectively; the IMU is used to measure the rolling, pitching and yawing attitudes of the remote sensing load; the gyro-stabilized platform generates a control signal according to the attitude reference input and the attitude measured by the IMU to drive the at least three torque motors to generate reaction torques; The data cables include: a one-to-five data cable (A) of the positioning and orientation system, a one-to-four switching cable (B) between the positioning and orientation system and the gyro-stabilized platform, a gyro-stabilized platform control cable (C), a data cable (D) for the control terminal to control the gyro-stabilized platform, a switching cable (E) between the positioning and orientation system and the remote sensing device, a one-to-two data cable (F) of the remote sensing device, a data cable (G) between the GNSS antenna and the positioning and orientation system, and a data cable (H) between the IMU and the positioning and orientation system; Among them, one end (a1) of the one-to-five data cable (A) of the positioning and orientation system is connected to the positioning and orientation system, and the other five ends include a first COM2 serial port end (a2), a first COM3 serial port end (a3), a first second pulse BNC interface end (a4), an Ethernet port end (a5) and a digital input and output serial port end (a6); one end (b1) of the one-to-four adapter cable (B) between the positioning and orientation system and the gyro-stabilized platform is connected to the third serial port end (c1) of the gyro-stabilized platform control cable (C), and the other end (b2) of the one-to-four adapter cable (B) between the positioning and orientation system and the gyro-stabilized platform is connected to the third serial port end (c1) of the gyro-stabilized platform control cable (C), and the other end (b3) of the one-to-four adapter cable (B) between the positioning and orientation system and the gyro-stabilized platform is connected to the third serial port end (c1) of the gyro-stabilized platform control cable (C), and the other end (b4) of the one-to-four adapter cable (B) between the positioning and orientation system and the gyro-stabilized platform The four terminals include a second COM2 serial port terminal (b2), a second COM3 serial port terminal (b3), a second pulse BNC interface terminal (b4) and an FMS serial port terminal (b5), which are respectively connected to the first COM2 serial port terminal (a2), the first COM3 serial port terminal (a3), the first second pulse BNC interface terminal (a4) and the RS-232 serial port terminal (d1) of the data cable (D); the control terminal (c2) of the gyro-stabilized platform control cable (C) is connected to the gyro-stabilized platform; The USB end (d2) of the data cable (D) is connected to the control terminal; the Ethernet port (a5) is connected to the control terminal; the digital input and output serial port (a6) is connected to the first serial port end (e1) of the adapter cable (E) between the positioning and orientation system and the remote sensing device; one end (f1) of the remote sensing device one-to-two data cable (F) is connected to the remote sensing device, and the other two ends include a second BNC interface end (f2) and a second serial port end (f3), which are respectively connected to the first BNC interface end (e2) of the adapter cable (E) between the positioning and orientation system and the remote sensing device and the industrial computer; the first TNC interface end (g1) of the data cable (G) between the GNSS antenna and the positioning and orientation system is connected to the positioning and orientation system, and the second TNC interface end (g2) is connected to the GNSS antenna; one end (h1) of the data cable (H) between the IMU and the positioning and orientation system is connected to the positioning and orientation system, and the other end (h2) of the data cable (H) between the IMU and the positioning and orientation system is connected to the IMU.

2. The device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements according to claim 1, characterized in that: The four corners of the bottom of the equipment cabinet are fixedly connected to the seat rails on the floor of the remote sensing aircraft; the equipment cabinet has three layers of aluminum plates, which are respectively fixedly connected to the industrial computer, the positioning and orientation system and the control terminal; an aluminum plate is installed on each side of the equipment cabinet, 6 circular holes are set on the first side aluminum plate, and 2 circular holes are set on the second side aluminum plate. The circular holes are used to insert, fix and isolate data cables between devices, and the distance between adjacent circular holes is twice the diameter of the circular holes; The six round holes on the first side aluminum plate correspond to the following data cables: The cable connecting the Ethernet port a5 and the control terminal; A cable connecting the first pulse-per-second BNC interface end (a4) and the second pulse-per-second BNC interface end (b4); A cable connecting the first COM3 serial port (a3) ​​and the COM3 serial port (b3); A cable connecting the first COM2 serial port (a2) and the second COM2 serial port (b2); The digital input and output serial port (a6) is connected to the first serial port (e1), and the first BNC interface (e2) is connected to the second BNC interface (f2); The connection between the second serial port (f3) and the industrial computer; The two round holes on the second side aluminum plate correspond to the following data cables: Data cable between GNSS antenna and positioning and orientation system (G) and data cable between IMU and positioning and orientation system (H).

3. The device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements according to claim 1, characterized in that: The remote sensing device, the gyro-stabilized platform, the industrial computer, the positioning and orientation system, and the control terminal are all equipped with grounding devices to prevent static electricity from damaging the devices; The grounding device includes: a screw, a nut, a plurality of nuts, a stainless steel support belt, and a grounding lead. The nut is installed on the upper part of the screw, and the plurality of nuts are installed in the middle part of the screw. One end of the grounding lead is fixed between the plurality of nuts and contacts the screw. The screw is fixed on the industrial computer, the positioning and orientation system, and the control terminal, and the other end of the grounding lead is fixed on the ground rail. Both ends of the stainless steel support belt are provided with annular sleeves, wherein one end of the annular sleeve is fixed to the bottom of the nut, and the other end of the annular sleeve is fixed to the lower part of the screw.

4. A control method for a device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements as claimed in claim 1 or 2, wherein the control terminal is installed with a Windows operating system, and the gyro-stabilized platform control software is installed in the Windows operating system, characterized in that: The method for controlling the gyro-stabilized platform by the gyro-stabilized platform control software comprises: A data cable (D) for controlling the gyro-stabilized platform by the control terminal is used to connect the control terminal and the gyro-stabilized platform, wherein the USB terminal (d2) is connected to the control terminal, the RS-232 serial port (d1) is connected to the FMS serial port (b5), the FMS serial port (b5) is connected to the third serial port (c1), and the control terminal (c2) is connected to the gyro-stabilized platform; Open the control terminal computer management program and click "Device Manager"; Click "Ports: COM and LPT"; Find the USB to serial communication port COM ,in, ; Open the gyro-stabilized platform control software and click "Communication Settings"; In the communication settings, select the COM port as the USB to serial communication port COM ; Click "Function Settings" and set the angle parameters in the function settings. The range of the roll angle is: ; The range of pitch angle is: ; The range of the declination angle is: ; In the function setting, select the type of remote sensing equipment; In the function setting, a vertical offset of the pitch angle is input, wherein the vertical offset of the pitch angle is equal to the angle between the plane where the gyro-stabilized platform is located and the sea level during flight; After completing the settings, enter the platform state. When the remote sensing aircraft is about to enter the flight route, click "Open stable platform", the gyro stabilized platform enters the adaptive control state and controls the remote sensing equipment to shoot vertically; at this time, the gyro stabilized platform continues to send gyro coded data to the positioning and orientation system through the second COM3 serial port (b3) and the second pulse BNC interface (b4); when the remote sensing aircraft completes the flight route, click "Close stable platform", the gyro stabilized platform returns to the original state and stops controlling the remote sensing equipment; After completing all routes according to the above method, turn off the gyro-stabilized platform control software.

5. A control method for a device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements as claimed in claim 1 or 2, wherein the control terminal is installed with a Windows operating system, and the positioning and orientation system control software is installed in the Windows operating system, characterized in that: The method for controlling the positioning and orientation system by the positioning and orientation system control software comprises: Use the one-to-five data cable (A) of the positioning and orientation system to connect the control terminal with the positioning and orientation system, wherein the Ethernet port (a5) is connected to the control terminal; Open the Network and Sharing Center of the control terminal, click Local Area Connection, click Properties, double-click Internet Protocol Version 4: TCP / IPv4, set the IP address to 129.100.0.25, and the subnet mask to 255.255.0.0; Open the positioning and orientation system control software, enter the setting interface, set the IP address of the positioning and orientation system to 129.100.0.100, and the subnet mask to 255.255.0.0; Set the IMU eccentricity component, GNSS eccentricity component and IMU installation angle; Set the RMS accuracy: attitude angle accuracy is 0.008-0.05 degrees, absolute azimuth accuracy is 0.008-0.05 degrees, position accuracy is 0.5-2 meters, and velocity accuracy is 0.05-0.5 meters per second; Set Event trigger rule: select positive edge trigger; Set the COM port: COM1 transmits GNSS data with a baud rate of 9600 and a frequency of 1Hz; the information receiver in COM2 selects the PAST1 format, the baud rate is 38400 and the frequency is 20Hz; the information receiver in COM3 selects the P30_GIM EncoderInput format, the baud rate is 38400 and the frequency is 1Hz; Set data recording parameters: select the data type to be recorded and set the recording frequency to 50Hz; After completing the settings, when the remote sensing aircraft takes off, turn on the positioning and orientation system, and observe the system's navigation mode, IMU status, GNSS receiver status, gyro-stabilized platform status, memory card status, and memory card available space in the control software. If the navigation mode is in calibration mode, the IMU status is normal, the GNSS receiver status is normal, the gyro-stabilized platform status is normal, the memory card is in idle state, and the memory card available space is greater than 50%, then the system can be determined to be normal; at this time, the positioning and orientation system continuously sends angular element data to the gyro-stabilized platform through the COM2 serial port; Observe the information of attitude angle accuracy, absolute azimuth accuracy, position accuracy and speed accuracy. If they all meet the above set accuracy, it can be determined that the system accuracy is normal; Start recording data. At this time, the positioning and orientation system starts to obtain the external orientation elements of the remote sensing equipment. After all routes are flown, stop recording data and turn off the positioning and orientation system control software during the aircraft's return process; The relationship between the gyro-stabilized platform and the positioning and orientation system is: the positioning and orientation system sends the roll angle, pitch angle and yaw angle to the gyro-stabilized platform through the COM2 serial port, which are used to correct the angular error of the gyro-stabilized platform; the gyro-stabilized platform sends the gyro encoding data to the positioning and orientation system through the COM3 serial port and the pulse-per-second BNC interface, which is used to calculate the dynamic eccentricity component of the GNSS antenna and IMU. There is no need to forcibly install the GNSS antenna within 10 cm from the photographic center of the remote sensing equipment, which provides a variety of options for the installation of the GNSS antenna.

6. A method for stabilizing the attitude of a remote sensing device and obtaining external orientation elements, which is implemented based on the device for stabilizing the attitude of a remote sensing device and obtaining its external orientation elements as claimed in any one of claims 1 to 3, characterized in that: The positioning and orientation system outputs the WGS84 rectangular coordinates of the IMU origin and the aircraft's roll angle , Pitch angle and declination include: According to the following formula: Solve for the exterior azimuth element ;in, It is the drawing coordinate system To Geocentric Coordinate System The rotation matrix of It is a geocentric coordinate system To local geographic coordinate system Rotation matrix, Is the local geographic coordinate system To IMU coordinate system The rotation matrix of is the IMU coordinate system To the remote sensing device coordinate system The rotation matrix of is the remote sensing device coordinate system To image space coordinate system The rotation matrix of Among them, the image space coordinate system The origin of is located at the image principal point, The axis points in the direction of flight, The axis points to the left of the image. Axially; Remote sensing equipment coordinate system The origin is at the center of photography. The axis points in the direction of flight, The axis points to the right of the remote sensing device. Axis downward; IMU Coordinate System The origin of is located at the center of the IMU gyroscope. The axis points in the direction of flight, The axis points to the right of the aircraft, Axis downward; Local geographic coordinate system Tangent to the reference ellipsoid, The axis points north, The axis points east, Axis downward; Geocentric Coordinate System The origin of is at the center of the reference ellipsoid, The axis points to the intersection of the equator and the Greenwich meridian. The axis points to the intersection of the equator and the 90° meridian. The axis points to the North Pole; Mapping coordinate system is an arbitrary local right-handed coordinate system specified by the user; According to the following formula: Solve for the exterior orientation line elements ,in, It is the eccentric component of the photographic center of the remote sensing equipment in the IMU coordinate system and is a known value.

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