Radar space synchronization rotation angle triggering device and control method
By designing a radar spatial synchronization rotation angle triggering device and using a photoelectric encoder to obtain accurate rotation angle information, the problem of coupling between the rotating synthetic aperture radar system and the servo device was solved, realizing the separation of the radar transceiver system and the servo drive device, thus improving monitoring accuracy and flexibility.
Patent Information
- Application Number
- CN202510999096.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-21
- Publication Date
- 2025-10-28
AI Technical Summary
Existing rotating synthetic aperture radar systems are highly coupled with servo devices, resulting in mechanical wear, complex and costly analog signal processing, and difficulty in meeting the accuracy requirements of different monitoring scenarios.
Design a radar spatial synchronization rotation angle triggering device, including a rotatable rotating arm, tilt sensor, photoelectric encoder and triggering circuit. The photoelectric encoder obtains accurate spatial rotation angle information, and the radar transceiver system is separated from the servo drive device by combining ABZ pulse signal.
This technology separates the radar transceiver system from the servo drive unit, simplifies the installation process, improves monitoring accuracy and flexibility, reduces equipment maintenance costs, and adapts to the needs of different monitoring scenarios.
Smart Images
Figure CN120847796A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of precision electromechanical control technology, specifically relating to a radar spatial synchronization rotation angle triggering device and control method. Background Technology
[0002] Rotating synthetic aperture radar systems can monitor the deformation of building facades. During deformation monitoring, centimeter-level or even millimeter-level monitoring accuracy is required. Deviations in position information will cause distance measurement errors, which in turn will prevent the radar echo signals from being maximized at the same point, resulting in defocusing, noise, and other effects. Therefore, precise spatial synchronization of position information is required.
[0003] Position information acquisition during the operation of rotating synthetic aperture radar (SAR) relies on mechanical devices. Sensors built into the rotating device acquire position information and transmit it to the radar, resulting in a high degree of coupling between existing SAR and servo systems. Current methods often rely on slip rings to feed position signals back to the rotating device. Slip rings experience mechanical wear during use, limiting their lifespan and requiring routine maintenance. Rotary transformers, as non-contact devices, offer lossless operation and high precision, but their transmitted signals are analog, requiring complex processing and are relatively expensive. Different monitoring scenarios have varying requirements for detail and detection accuracy, necessitating radar transceiver systems with different apertures and frequency bands to achieve high-precision monitoring. This necessitates the separation of radar equipment from mechanical servo devices to address diverse monitoring scenarios. Summary of the Invention
[0004] The purpose of this invention is to address the problem of coupling between existing rotating synthetic aperture radar systems and servo devices by designing a rotation angle triggering device and control method for radar spatial synchronization, thereby achieving spatial synchronization of the rotating synthetic aperture radar system.
[0005] The radar space synchronization rotation angle triggering device of the present invention includes a rotatable rotating arm, on which a radar transceiver system, an angle sensor for detecting the angle of the rotating arm, a triggering circuit and an optoelectronic encoder assembly are mounted.
[0006] The photoelectric encoder assembly includes a photoelectric encoder mounted on a rotating arm and capable of rotating with the rotating arm, and a photoelectric encoder shaft that does not rotate with the rotating arm.
[0007] The triggering circuit includes a photoelectric encoder decoding module connected to the photoelectric encoder, a positive orientation correction module connected to the tilt sensor, and a comparator connected to the photoelectric encoder decoding module, the positive orientation correction module, the angle trigger table, the trigger table maximum cycle count register, and the cycle count counter. The comparator and the positive orientation correction module are also connected to the radar transceiver system. The tilt sensor is set with its X-axis direction aligned with the arm length direction of the rotating arm, and its Y-axis aligned with the axis direction of the rotating arm during rotation.
[0008] Preferably, the rotating arm further includes a rotating mechanism for driving the rotating arm to rotate. The rotating mechanism includes a rotating head fixed at the center of the rotating arm. The rotating head is connected to a servo drive device below. The servo drive device includes a drive motor, a drive gear connected to the output shaft of the drive motor, a driven gear meshing with the drive gear, and a fixed shaft fixed at the center of the driven gear. The driven gear is fixedly connected to the rotating head.
[0009] Preferably, the triggering device further includes a meshing crown gear mounted on the lower end face of the photoelectric encoder shaft and a fixed crown gear mounted on a fixed shaft, wherein the meshing crown gear and the fixed crown gear mesh with each other.
[0010] Preferably, the rotating arm has a through hole at its center, through which the photoelectric encoder shaft passes. The upper surface around the center of the rotating arm has multiple screw holes, and the photoelectric encoder is fixed to the upper surface of the rotating arm by bolts. The lower surface around the center of the rotating arm also has multiple screw holes, and the rotating arm is fixedly connected to the rotating head below by bolts.
[0011] Preferably, the photoelectric encoder decoding module, the positive vertical correction module, the comparator, the angle trigger table, the trigger table maximum cycle count register, and the cycle count counter of the trigger circuit are all implemented using a single FPGA program.
[0012] This invention also discloses a rotation angle triggering control method for radar spatial synchronization, based on the aforementioned spatial synchronization triggering device, comprising the following steps:
[0013] Step 1. Power on and initialize the system. Set the initial value of the loop count counter to zero and assign an initial value to the loop count counter.
[0014] After initialization, the photoelectric encoder outputs an ABZ pulse signal; the rotating arm rotates and drives the photoelectric encoder to rotate. When the Z signal output by the photoelectric encoder is received, the encoding rotation angle output by the photoelectric encoder when the Z signal is output is defined as 0 degrees.
[0015] The photoelectric encoder decoding module starts counting based on the A and B signals of the photoelectric encoder to obtain the rotation angle value defined by the coded rotation angle;
[0016] Step 2. The rotating arm continues to rotate. When the absolute rotation angle detected by the tilt sensor is X-axis direction +90 degrees, the photoelectric encoder decoding module outputs the coded rotation angle value, which is the rotation angle difference Δ between the photoelectric encoder zero point and the radar transceiver system when they are directly above each other, and transmits this rotation angle difference Δ to the radar transceiver system.
[0017] Step 3. After receiving the rotation angle difference Δ, the radar transceiver system calculates the trigger pulse node angle value and generates angle trigger table data according to the synthetic aperture imaging requirements. The angle trigger table data and the number of cycles of the trigger table are then sent back and stored in the angle trigger table and the maximum number of cycles of the trigger table register.
[0018] Step 4. The trigger circuit acquires the current encoding rotation angle θ detected by the photoelectric encoder. The comparator compares θ with the values in the angle trigger table one by one. When θ matches one of the values S in the table, the trigger circuit will trigger the triggering circuit. k When they are equal, the comparator sends a trigger pulse to the radar transceiver system and marks the S in the table. k ;
[0019] If all S in the table k All values are marked, indicating that after traversing the angle trigger table 203 once, the value of the loop count counter 206 is incremented by 1;
[0020] Step 5. After receiving the trigger pulse, the radar transceiver system transmits and samples the echo;
[0021] Step 6. If the value of the loop count counter is less than the value of the trigger table maximum loop count register, continue to step 4; otherwise, proceed to step 7.
[0022] Step 7. After the echo data is received, the radar system performs imaging processing and resets the current value of the cycle count counter to zero.
[0023] Preferably, in step 5, the specific process of radar transmission and echo sampling is as follows:
[0024] The radar transmits a linear frequency modulated continuous wave, receives the target echo, removes the skew from the echo data to obtain the echo intermediate frequency data, samples the echo intermediate frequency data, and receives and stores the digitized echo intermediate frequency data via the TFTP protocol.
[0025] Preferably, the specific method for generating the angle trigger table data in step 3 is as follows: calculating the trigger pulse node angle, wherein the trigger pulse node angle formula is expressed as:
[0026] S k=mod((Δ+k*|SA|),360)), k=0,1,2...N-1; mod represents modulo operation, N=360 / SA, SA is the set trigger interval angle, N times S k The value is stored in the angle trigger table as data in the angle trigger table.
[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0028] 1. This invention places the photoelectric encoder on the axis of the rotating arm, enabling the radar to acquire its own precise spatial rotation angle information in real time without using rotating connectors such as slip rings and rotary transformers. Combined with ABZ pulse signal detection, the trigger position no longer depends on the radar servo drive device, thereby realizing the separation of the radar transceiver system and the servo drive device. When the rotating synthetic aperture radar is used for deformation monitoring, different frequency bands and aperture radar systems can be selected by replacing the rotating arm and its components as a whole.
[0029] 2. The fixed crown gear of the crown gear meshing servo drive device and the crown gear on the photoelectric encoder shaft are used so that when the rotating arm assembly is installed on the servo drive device, the teeth between the crown gears are automatically aligned and meshed to fix it, eliminating the need for alignment operations and making the installation process convenient and simple.
[0030] 3. By using the tilt sensor installed on the rotating arm, the automatic sensing of the rotation angle directly above the radar transceiver system is completed, thereby obtaining the spatial angular position relationship of the rotating arm assembly. This avoids the need to align the zero point of the photoelectric encoder with the reference point of the servo drive device during installation to obtain the spatial angular position relationship of the rotating arm assembly. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of a specific embodiment of the radar spatial synchronization rotation angle triggering device of the present invention;
[0032] Figure 2 This is a schematic diagram of a specific embodiment of the trigger circuit described in this invention;
[0033] Figure 3 This is a schematic flowchart of a specific implementation of the radar spatial synchronization rotation angle triggering control method of the present invention.
[0034] Figure 4 This is a waveform diagram of a specific embodiment of the ABZ signal described in this invention.
[0035] The attached figures are labeled as follows: Radar transceiver system-101, tilt sensor-102, trigger circuit-103, power supply battery-104, photoelectric encoder shaft-105, photoelectric encoder-106, counterweight-107, rotating arm-108, rotating head-109, driven gear-110, fixed shaft-111, drive gear-112, drive motor-113, servo drive device-114, fixed crown gear-115, meshing crown gear-116, bolt-117, photoelectric encoder decoding module-201, positive vertical alignment correction module-202, angle trigger table-203, trigger table maximum cycle count register-204, comparator-205, and cycle count counter-206. Detailed Implementation
[0036] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0037] The rotation angle triggering device of the present invention, such as Figure 1 As shown, it includes a hollow rotating arm 108 made of aluminum alloy, and a radar transceiver system 101, tilt sensor 102, trigger circuit 103, power supply battery 104, photoelectric encoder 106 and counterweight 107 located on the rotating arm 108; the trigger device also includes a hollow rotating head 109, and the center of the rotating arm is fixedly connected to the top of the rotating head.
[0038] The rotating head is connected to the servo drive device 114 below. The servo drive device 114 includes a drive motor 113, a drive gear 112 connected to the output shaft of the drive motor, a driven gear 110 meshing with the drive gear 112, and a fixed shaft 111 fixed to the central through hole of the driven gear for limiting the rotation of the driven gear. The driven gear is fixedly connected to the rotating head. A fixed crown gear 115 is provided on the upper end face of the fixed shaft 111.
[0039] The rotating arm has a through hole in the center. The triggering device also includes a photoelectric encoder shaft 105 installed in the through hole in the center of the rotating arm. The lower end face of the photoelectric encoder shaft 105 has a meshing crown gear 116 for meshing with the fixed crown gear 115. The fixed crown gear 115 and the meshing crown gear 116 have the same diameter, the same number of teeth and the same tooth type.
[0040] The radar transceiver system is an existing technology in this field, including transceiver antennas, radio frequency modules, filters, amplifiers, sampling circuits, etc., to realize the functions of transmitting, receiving and sampling radar waves for synthetic aperture imaging.
[0041] The photoelectric encoder 106 can be selected as a 90,000-line incremental photoelectric encoder. When the photoelectric encoder 106 rotates 360 degrees / 90,000 = 0.004 degrees relative to the photoelectric encoder shaft 105, it outputs a set of orthogonal A / B pulse signals. The A / B pulse signals include two pulse signals with a 90-degree phase difference and the same high and low levels.
[0042] In one specific embodiment, a radar transceiver system 101, a tilt sensor 102, a trigger circuit 103, and a power supply battery 104 are installed at one end of the rotating arm, and a counterweight 107 is installed at the other end of the rotating arm.
[0043] A through hole is formed in the center of the rotating arm 108, through which the photoelectric encoder shaft 105 passes. Multiple screw holes are formed on the upper surface around the center of the rotating arm 108, and the photoelectric encoder 106 is fixed to the upper surface of the rotating arm 108 by bolts 117. Multiple screw holes are also formed on the lower surface around the center of the rotating arm 108, and the rotating arm 108 is fixedly connected to the rotating head 109 below by bolts 117.
[0044] The meshing crown gear 116 on the lower end face of the photoelectric encoder shaft 105 meshes with the fixed crown gear 115 mounted on the fixed shaft 111, so that the photoelectric encoder shaft 105 and the body of the servo drive device 114 are fixed together and do not rotate with the rotating arm 108.
[0045] The photoelectric encoder shaft 105 is fixed by the meshing of the crown gears and will not rotate with the rotation of the rotating arm 108 and the photoelectric encoder 106. The photoelectric encoder shaft 105 and the photoelectric encoder 106 are connected by a rotating shaft. The rotation of the photoelectric encoder 106 will not drive the photoelectric encoder shaft 105 to rotate. The photoelectric encoder assembly and the meshing crown gear 116 are assembled into a whole component, which can be directly connected to the rotating arm 108. The photoelectric encoder 106 in the photoelectric encoder assembly is fixedly connected to the rotating arm 108, so that the photoelectric encoder assembly, the rotating arm 108, the meshing crown gear 116, and other components installed on the rotating arm 108, such as the radar transceiver system 101, the tilt sensor 102, the trigger circuit 103, the power supply battery 104, the counterweight 107, etc., form a whole radar assembly, which can realize different radar detection requirements. When the radar needs to be replaced, the rotating head 109 is separated from the rotating arm 108, and the whole radar assembly is separated from the rotating head to replace other whole radar assemblies.
[0046] In the servo drive device 114, the drive motor 113 drives the driven gear 110 to rotate through the drive gear 112, thereby driving the rotating head 109 and the rotating arm 108, which are fixed together with the driven gear 110, to rotate simultaneously. The photoelectric encoder 106 outputs ABZ pulse signals to indicate the current rotation angle of the rotating arm 108.
[0047] During installation, the X-axis of the tilt sensor 102 is aligned with the length of the rotating arm 108, and the Y-axis is aligned with the axis of rotation of the rotating arm, i.e., the axial direction of the photoelectric encoder shaft 105. The X-axis output is set to 0 when the rotating arm 108 is parallel to the ground. ° When the radar transceiver system 101 is located directly above the axis of rotation, i.e., the rotating arm is perpendicular to the radar's mounting ground, the X-axis output is +90. ° When the rotation plane of the rotating arm 108 is perpendicular to the ground, the Y-axis output is 0. ° .
[0048] like Figure 2 As shown, the trigger circuit 103 in this invention can be used for data processing and communication via an FPGA. The trigger circuit 103 includes a photoelectric encoder decoding module 201, a positive vertical correction module 202, an angle trigger table 203, a trigger table maximum cycle count register 204, a comparator 205, and a cycle count counter 206. Each of these modules can be implemented using hardware programming on an FPGA.
[0049] The photoelectric encoder decoding module 201 receives the ABZ pulse signal output by the photoelectric encoder 106. A typical waveform of the ABZ pulse signal is as follows: Figure 4 As shown, when the Z signal's transition edge is received, the output angle value is 0, and the position at this time is defined as the zero point of the photoelectric encoder's encoding rotation angle; when the AB quadrature pulse signal is received, if pulse A is earlier than pulse B, it indicates that the rotating arm rotates clockwise, and the decoding module outputs an angle value of +0.004 degrees; if pulse A is later than pulse B, it indicates counterclockwise rotation, and the output angle value is -0.004 degrees.
[0050] The upward positioning correction module 202, when the absolute rotation angle of the rotating arm detected by the tilt sensor 102 is +90 degrees on the X-axis, indicates that the radar transceiver system 101 is directly above. The angle value output by the photoelectric encoder decoding module 201 is the difference Δ between the zero point and the upward rotation angle. This difference Δ is sent to the radar transceiver system 101 to generate an angle trigger table. The tilt sensor 102 communicates with the upward positioning correction module 202 in the trigger circuit 103 via an RS485 serial port.
[0051] The storage size of the angle trigger table 203 and the value assigned to the trigger table maximum cycle count register 204 are determined by the radar transceiver system 101 based on the synthetic aperture imaging requirements and the rotation angle difference Δ.
[0052] The current encoder rotation angle θ detected by the photoelectric encoder 106 is obtained. The comparator 205 compares θ with the values in the angle trigger table 203 one by one. When θ matches one of the values S in the table, the encoder triggers the rotation angle θ. kWhen they are equal, the comparator sends a trigger pulse to the radar transceiver system 101 and marks the S in the table. k ;
[0053] If all S in the table k All values are marked, indicating that the angle trigger table 203 has been traversed once.
[0054] The loop count counter 206 increments by 1 after each iteration of the angle trigger table, starting from 0.
[0055] The triggering device is powered by a power supply battery 107 mounted on the rotating arm 108. The power supply battery is a 12V DC power supply. After transformation and regulation, it generates a 5V power supply to power the triggering circuit 103, the photoelectric encoder 106 and the tilt sensor 102, and outputs a 12V voltage to power the radar transceiver system 101.
[0056] like Figure 3 As shown, a rotation angle triggering control method for spatial synchronization of a radar system includes the following specific steps:
[0057] Step 1. After the system is powered on, the radar transceiver system 101 and the trigger circuit 103 will be initialized. During the initialization process, the radar transceiver system 101 first establishes TFTP (Trivial File Transfer Protocol) communication. During the initialization process, the trigger circuit 103 sets the initial values of the angle trigger table 203 and the cycle count counter 206 to 0, waits for the photoelectric encoder 106 to output the Z signal, and sets the maximum cycle count register 204 of the trigger table to the initial value of 0, which is the set number of cycles.
[0058] The photoelectric encoder 106 starts outputting ABZ pulse signals. At the same time, the servo drive device 114 is activated, driving the rotating arm 108 to rotate. When the Z signal output by the photoelectric encoder 106 is received, the encoding rotation angle output by the photoelectric encoder 106 when outputting the Z signal is defined as 0 degrees.
[0059] The photoelectric encoder decoding module 201 in the trigger circuit 103 starts counting based on the A and B signals of the photoelectric encoder 106 to obtain the rotation angle value defined by the coded rotation angle.
[0060] Step 2. The rotating arm 108 continues to rotate. When the absolute rotation angle detected by the tilt sensor is X-axis direction +90 degrees, since 0 degrees has been defined in step 1 and the angle is judged by counting AB pulse signals starting from 0 degrees, the angle value output by the photoelectric encoder decoding module 201 at this time is the difference Δ between the zero point of the photoelectric encoder and the rotation angle directly above, and the angle value is transmitted to the radar transceiver system 101.
[0061] Step 3. After receiving the angle value Δ located directly above it, the radar transceiver system 101 generates angle trigger table data according to the synthetic aperture imaging requirements, and sends the angle trigger table data and the number of cycles of the trigger table back to the trigger circuit 103, and stores them in the angle trigger table 203 and the trigger table maximum cycle count register 204, respectively.
[0062] The number of cycles is set according to the synthetic aperture imaging requirements of the radar. The higher the required gain, the higher the number of cycles. In this embodiment, the number of cycles is set to 2. The generation rule of the angle trigger table 203 is to generate trigger pulses at a trigger interval angle of SA = 0.36 degrees, that is, 1000 trigger pulse signals are generated for each rotation. The data stored in the angle trigger table 203 is the trigger pulse node angle S. k The formula for the trigger pulse node angle is expressed as follows:
[0063] S k =mod((Δ+k*0.36),360)), k=0,1,2...999; mod represents the modulo operation, which modifies 1000 S... k The values are stored as angle trigger table data in angle trigger table 203. If the loop count is 2, a total of 2000 trigger pulse signals will be output.
[0064] Through steps 1 to 3, multiple trigger pulse node angle data are stored in the angle trigger table 203. These angle data are defined by the coded rotation angle of the photoelectric encoder 106, and take into account the absolute rotation angle of the rotating arm 108 detected by the tilt sensor 102. When detecting the rotation point and trigger pulse in the future, the detection data of the photoelectric encoder 106 can be directly read for comparison and judgment.
[0065] Based on the synthetic aperture radar imaging requirements, the trigger interval angle SA and the number of cycles are set. In subsequent steps, pulse signals that meet the imaging requirements can be generated to obtain sufficient echo signals for imaging.
[0066] Step 4. The trigger circuit 103 obtains the encoding rotation angle θ detected by the current photoelectric encoder 106. The comparator 205 compares θ with the value in the angle trigger table 203 one by one. When the two are equal, the comparator sends a trigger pulse to the radar transceiver system 101. If the angle trigger table 203 is traversed once, the value of the cycle count counter 206 is incremented by 1.
[0067] Step 5. After receiving the trigger pulse, the radar transceiver system 101 transmits a linear frequency modulated continuous wave, receives the target echo, removes the skew from the echo data to obtain the echo intermediate frequency data, samples the echo intermediate frequency data at a sampling rate of 20MHz, and receives and stores the digitized echo intermediate frequency data via the TFTP protocol.
[0068] Step 6. If the value of the loop count counter 206 is less than the value of the trigger table maximum loop count register 204, then continue to step 4. When the value of the loop count counter 206 is equal to the value of the trigger table maximum loop count register 204, it means that the loop count has been reached, then proceed to step 7.
[0069] Step 7. Once the echo data is received, the radar system performs imaging processing.
[0070] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0071] 1. The present invention places the photoelectric encoder on the axis of rotation of the rotating arm, which enables the radar to acquire its own precise spatial rotation angle information in real time without using rotating connectors such as slip rings and rotary transformers. Combined with ABZ pulse signal detection, the trigger position no longer depends on the radar servo drive device, thereby realizing the separation of the radar transceiver system and the servo drive device. When the rotating synthetic aperture radar is used for deformation monitoring, different frequency bands and aperture radar systems can be selected by replacing the rotating arm and its components as a whole.
[0072] 2. The fixed crown gear of the crown gear meshing servo drive device and the crown gear on the photoelectric encoder shaft are used so that when the rotating arm assembly is installed on the servo drive device, the teeth between the crown gears are automatically aligned and meshed to fix it, eliminating the need for alignment operations and making the installation process convenient and simple.
[0073] 3. By using the tilt sensor installed on the rotating arm, the automatic sensing of the rotation angle directly above the radar transceiver system is completed, thereby obtaining the spatial angular position relationship of the rotating arm assembly. This avoids the need to align the zero point of the photoelectric encoder with the reference point of the servo drive device during installation to obtain the spatial angular position relationship of the rotating arm assembly.
[0074] The foregoing descriptions are preferred embodiments of the present invention. Unless there is a clear contradiction between the preferred embodiments or a prerequisite for a particular preferred embodiment, the preferred embodiments can be arbitrarily combined and used. The embodiments and specific parameters described are only for clearly illustrating the inventor's invention verification process and are not intended to limit the scope of patent protection of the present invention. The scope of patent protection of the present invention shall still be determined by its claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.
Claims
1. A radar spatial synchronization rotation angle triggering device, characterized in that, It includes a rotatable rotating arm (108) on which a radar transceiver system (101), an angle sensor (102) for detecting the angle of the rotating arm, a trigger circuit (103) and an optical encoder assembly are mounted; The photoelectric encoder assembly includes a photoelectric encoder (106) mounted on a rotating arm (108) and rotatable with the rotating arm, and a photoelectric encoder shaft (105) that serves as the rotating shaft of the photoelectric encoder but does not rotate with the rotating arm. The trigger circuit includes an optoelectronic encoder decoding module (201) connected to the optoelectronic encoder, a positive upward position correction module (202) connected to the tilt sensor (102), and a comparator (205). The comparator (205) is connected to the optoelectronic encoder decoding module (201), the positive upward position correction module (202), the angle trigger table (203), the trigger table maximum cycle count register (204), and the cycle count counter (206). The comparator (205) and the positive upward position correction module (202) are also connected to the radar transceiver system (101). The X-axis of the tilt sensor (102) is set to be the same as the arm length direction of the rotating arm (108), and the Y-axis is the same as the axis direction when the rotating arm rotates.
2. The radar spatial synchronization rotation angle triggering device as described in claim 1, characterized in that, The rotating arm also includes a rotating mechanism for driving the rotating arm to rotate. The rotating mechanism includes a rotating head (109) fixed at the center of the rotating arm. The rotating head is connected to a servo drive device (114) below. The servo drive device (114) includes a drive motor (113), a drive gear (112) connected to the output shaft of the drive motor, a driven gear (110) meshing with the drive gear (112), and a fixed shaft (111) fixed at the center of the driven gear. The driven gear (110) is fixedly connected to the rotating head (109).
3. The radar spatial synchronization rotation angle triggering device as described in claim 2, characterized in that, The triggering device also includes a meshing crown gear (116) mounted on the lower end face of the photoelectric encoder shaft and a fixed crown gear (115) mounted on a fixed shaft (111), wherein the meshing crown gear (116) and the fixed crown gear (115) mesh with each other.
4. The radar spatial synchronization rotation angle triggering device as described in claim 2 or 3, characterized in that, The rotating arm (108) has a through hole in the center, through which the photoelectric encoder shaft (105) passes. The upper surface of the rotating arm (108) around the center has multiple screw holes. The photoelectric encoder (106) is fixed to the upper surface of the rotating arm (108) by bolts (117). The lower surface of the rotating arm (108) around the center also has multiple screw holes. The rotating arm (108) is fixedly connected to the rotating head (109) below by bolts (117).
5. The radar spatial synchronization rotation angle triggering device as described in claim 1, characterized in that, The photoelectric encoder decoding module, the positive vertical correction module, the comparator, the angle trigger table, the trigger table maximum cycle count register, and the cycle count counter of the trigger circuit are all implemented using a single FPGA program.
6. A method for triggering rotation angle for radar spatial synchronization, characterized in that, Based on the spatial synchronization triggering device as described in any one of claims 1 to 5, the method includes the following steps: Step 1. Power on and initialize the system. Set the initial value of the loop count counter to zero and assign an initial value to the loop count counter. After initialization, the photoelectric encoder outputs an ABZ pulse signal; the rotating arm rotates and drives the photoelectric encoder to rotate. When the Z signal output by the photoelectric encoder is received, the encoding rotation angle output by the photoelectric encoder when the Z signal is output is defined as 0 degrees. The photoelectric encoder decoding module starts counting based on the A and B signals of the photoelectric encoder to obtain the rotation angle value defined by the coded rotation angle; Step 2. The rotating arm continues to rotate. When the absolute rotation angle detected by the tilt sensor is X-axis direction +90 degrees, the angle value of the coded rotation angle output by the photoelectric encoder decoding module is recorded as the rotation angle difference Δ, and the rotation angle difference Δ is transmitted to the radar transceiver system. Step 3. After receiving the rotation angle difference Δ, the radar transceiver system calculates the trigger pulse node angle value and generates angle trigger table data according to the synthetic aperture imaging requirements. The angle trigger table data and the number of cycles of the trigger table are then sent back and stored in the angle trigger table and the maximum number of cycles of the trigger table register. Step 4. The trigger circuit acquires the current encoding rotation angle θ detected by the photoelectric encoder. The comparator compares θ with the values in the angle trigger table one by one. When θ matches the angle value S of a trigger pulse node in the angle trigger table, the circuit will trigger the trigger circuit. k When they are equal, the comparator sends a trigger pulse to the radar transceiver system and marks the S in the table. k ; If all S in the table k All values are marked, indicating that the value of the loop count counter 206 is incremented by 1 after one iteration of the angle trigger table; Step 5. After receiving the trigger pulse, the radar transceiver system transmits and samples the echo; Step 6. If the value of the loop count counter is less than the value of the trigger table maximum loop count register, continue to step 4; otherwise, proceed to step 7. Step 7. After the echo data is received, the radar system performs imaging processing and resets the current value of the cycle count counter to zero.
7. The triggering method as described in claim 6, characterized in that, In step 5, the specific process of radar transmission and echo sampling is as follows: The radar transmits a linear frequency modulated continuous wave, receives the target echo, removes the skew from the echo data to obtain the echo intermediate frequency data, samples the echo intermediate frequency data, and receives and stores the digitized echo intermediate frequency data via the TFTP protocol.
8. The triggering method as described in claim 6, characterized in that, The specific method for generating the angle trigger table data in step 3 is as follows: The trigger pulse node angle is calculated using the following formula: S k =mod((Δ+k*|SA|),360)), k=0,1,2...N-1; mod represents modulo operation, N=360 / SA, SA is the set trigger interval angle, N times S k The value is stored in the angle trigger table as data in the angle trigger table.