Method and system for outputting ACP and ARP signals based on absolute encoder

Abstract

The present invention relates to a method and system for outputting ACP and ARP signals based on an absolute encoder, belonging to the field of signal processing technology, and solving the problem that the existing system does not use an absolute encoder to output ACP and ARP signals and the algorithm for changing the accuracy of the output ACP signal is complex. The method includes: a turntable control board communicates with an absolute encoder, collects binary position information, and calculates the turntable speed and turntable direction; the turntable control board obtains the true north zero position information, and subtracts the binary true north zero position information from the binary position information to obtain a relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the control board to output an ARP signal; when the turntable speed is not 0, according to the ACP signal accuracy sent by the radar main system and the length of the binary position information, the level signal at the corresponding position is taken out from the relative azimuth signal as an ACP signal output; the turntable control board uploads the turntable speed and turntable direction to the radar main system. The absolute encoder outputs ACP and ARP signals.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and in particular to a method and system for outputting ACP and ARP signals based on an absolute encoder. Background Art

[0002] Air traffic control radar scans targets by rotating the antenna and calculating the azimuth of the scanning antenna based on the azimuth increment pulse (ACP signal) output by the encoder. The azimuth is relative to the true north position, which is determined by the true north zero position pulse (ARP signal) output by the encoder. Therefore, when assembling various encoders, it is necessary to ensure that the turntable can output ACP and ARP signals.

[0003] In the field of radar antenna servo turntable, there are many types of encoders. Considering the accuracy, installation and reliability, photoelectric encoders are generally selected. Photoelectric encoders can be divided into incremental photoelectric encoders and absolute encoders.

[0004] The general design is that the turntable uses an incremental encoder. Although this encoder has the advantages of high resolution, low price, and simple interface, it does not have a power-off memory function, and its anti-interference and stability are not as good as those of an absolute encoder, so its selection occasions are limited. In addition, when using an incremental encoder, the direction of the turntable movement is determined based on the A and B phase relationship, and the A phase is in the front for positive rotation; generally, the ACP signal accuracy is the encoder resolution, because the radar main system determines the direction of the turntable movement based on the A / B phase relationship. If you want to change the ACP signal accuracy, you need to write two counter programs to read the A / B phase pulses. Therefore, the logic timing requirements for the counter program are high. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a method and system for outputting ACP and ARP signals based on an absolute encoder, so as to solve the problem that the existing system does not use an absolute encoder to output ACP and ARP signals and the algorithm for changing the accuracy of the output ACP signal is complex.

[0006] On the one hand, an embodiment of the present invention provides a method for outputting ACP and ARP signals based on an absolute encoder, comprising the following steps:

[0007] After power is turned on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction;

[0008] The turntable control board obtains the true north zero position information sent by the radar main system, subtracts the binary true north zero position information from the binary position information, and obtains the relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output the ARP signal;

[0009] When the turntable speed is not 0, according to the accuracy of the ACP signal sent by the radar main system and the length of the binary position information, the level signal on the corresponding bit is taken from the relative azimuth signal as the ACP signal output;

[0010] The turntable control board periodically uploads the turntable speed and direction to the radar main system.

[0011] Based on the further improvement of the above method, the method also includes: the radar main system updates the radar antenna position according to the received turntable direction and ACP and ARP signals.

[0012] Based on the further improvement of the above method, the length of the binary position information is consistent with the number of valid bits n of the data of the absolute encoder;

[0013] Calculate the turntable speed and turntable direction, including:

[0014] Convert the binary position information collected each time into floating-point data of 0° to 360°, and then multiply it by the resolution of the absolute encoder to obtain the position value to be calculated;

[0015] The difference between the two adjacent collected position values ​​to be calculated is divided by the sampling period to obtain the turntable speed;

[0016] When the turntable speed is a positive value, the turntable direction is forward; when the turntable speed is a negative value, the turntable direction is reverse.

[0017] Based on further improvement of the above method, the north zero position information sent by the radar main system is obtained, including: the north zero position information sent by the radar main system in real time, or the north zero position information last sent by the radar main system and stored in the turntable control board before power-on.

[0018] Based on the further improvement of the above method, the true north zero position information converted into binary includes:

[0019] The turntable control board converts the acquired floating point true north zero position information of 0° to 360° into 32-bit binary true north zero position information as the original binary;

[0020] According to the number of valid bits n of the data of the absolute encoder, the lower n bits of the original binary are taken as the binary true north zero position information.

[0021] Based on the further improvement of the above method, when the relative bearing signal is 0, any of the following conditions is met:

[0022] The upper two bits of the relative position signal of the previous sampling period are 00, and the upper two bits of the relative position signal of the current sampling period are 11;

[0023] or,

[0024] The upper two bits of the relative position signal of the previous sampling cycle are 11, and the upper two bits of the relative position signal of the current sampling cycle are 00.

[0025] Based on further improvements to the above method, the accuracy of the ACP signal sent by the radar main system is less than the length of the binary position information.

[0026] Based on the further improvement of the above method, according to the ACP signal accuracy m sent by the radar main system and the length n of the binary position information, the level signal on the corresponding bit is taken out from the relative azimuth signal as the ACP signal output, that is, the nmth bit level signal in the relative azimuth signal is output as the ACP signal.

[0027] Based on the further improvement of the above method, the radar main system updates the radar antenna position according to the received turntable direction and ACP and ARP signals, including:

[0028] When the radar main system receives an ACP signal, if the turntable is in the forward direction, the current position of the radar antenna is adjusted by +360° / 2 m ; If the turntable direction is reverse, the current position of the radar antenna is -360° / 2 m , where m represents the ACP signal accuracy;

[0029] Every time the radar main system receives an ARP signal, the current position of the radar antenna is updated to 0°.

[0030] On the other hand, an embodiment of the present invention provides a system for outputting ACP and ARP signals based on an absolute encoder, comprising: an absolute encoder, a turntable control board and a radar main system; wherein,

[0031] Absolute encoder, used to communicate with the turntable control board and send binary position information;

[0032] The turntable control board is used to communicate with the absolute encoder and the radar main system. After power-on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction; the turntable control board obtains the true north zero position information sent by the radar main system, subtracts the binary true north zero position information from the binary position information, and obtains the relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output the ARP signal; when the turntable speed is not 0, according to the ACP signal accuracy sent by the radar main system and the length of the binary position information, the level signal on the corresponding position is taken out from the relative azimuth signal as the ACP signal output; the turntable control board periodically uploads the turntable speed and turntable direction to the radar main system;

[0033] The radar main system is used to send the true north zero position information or ACP signal accuracy to the turntable control board; update the radar antenna position according to the received turntable direction and ACP and ARP signals.

[0034] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0035] 1. The function of outputting ACP and ARP signals of the radar antenna turntable equipped with absolute encoder is realized, which eliminates the restriction that only incremental encoder can be selected when the radar antenna system needs the turntable to send ACP and ARP signals;

[0036] 2. It can be widely used in radar antenna turntable equipment, so that it can not only output the ACP signal and ARP signal required by the radar main system, but also continue to have the advantages of absolute encoder such as compact structure, strong anti-interference ability, power-off memory function, etc., and the ACP signal accuracy is optional and the algorithm is simple, which improves the applicability of the turntable.

[0037] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0039] Figure 1 This is a flow chart of a method for outputting ACP and ARP signals based on an absolute encoder according to Embodiment 1 of the present invention;

[0040] Figure 2 This is an example diagram of the system hardware structure of the ACP and ARP signals output based on the absolute encoder according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0042] The air traffic control radar scans the target by rotating the antenna and calculating the azimuth of the scanning antenna by receiving the azimuth increment pulse (ACP signal). The azimuth is relative to the true north position and is determined by the true north zero position pulse (ARP signal) received by the radar. The turntable is used to carry and drive the antenna to scan and rotate in azimuth, and can realize the information interconnection between the antenna and other units through the internal low-frequency conductive slip ring and high-frequency joint. The turntable itself also communicates with the radar main system, receives instructions from the radar main system, uploads motion status information, processes the internal encoder information when the radar main system needs it, and outputs the ACP and ARP signals required by the radar main system.

[0043] Example 1

[0044] A specific embodiment of the present invention discloses a method for outputting ACP and ARP signals based on an absolute encoder, such as Figure 1 As shown, the following steps are included:

[0045] S11: After power-on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction.

[0046] It should be noted that the turntable is powered on and the control board runs the program; the turntable control board and the absolute encoder use RS422 communication method to send SSI excitation clock pulse signals to the absolute encoder; the absolute encoder sends binary position information to the turntable control board. The length of the binary position information is consistent with the number of valid bits n of the absolute encoder data, expressed as encoder_data[n].

[0047] Specifically, the turntable speed and turntable direction are calculated, including:

[0048] ①Convert the binary position information collected each time into floating-point data of 0° to 360°, and then multiply it by the resolution of the absolute encoder to obtain the position value to be calculated;

[0049] It should be noted that the resolution of an absolute encoder refers to the minimum value that the encoder can measure, expressed as 360 / 2 n , where n represents the number of valid bits of data for the absolute encoder.

[0050] For example, the effective number of bits of the hexadecimal encoder is 16, and the resolution is 360 / 2 16 =0.0055. If the binary position information is 01000000000000000, it is converted to decimal as 16384. Multiplying by 0.0055, the position value to be calculated is 90°.

[0051] ② The difference between the two adjacent collected position values ​​to be calculated is divided by the sampling period to obtain the turntable speed;

[0052] ③ When the turntable speed is a positive value, the turntable direction is forward; when the turntable speed is a negative value, the turntable direction is reverse.

[0053] S12: The turntable control board obtains the true north zero position information sent by the radar main system, subtracts the binary true north zero position information from the binary position information, and obtains a relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output an ARP signal.

[0054] It should be noted that since the absolute encoder has a power-off memory function, the turntable control board obtains the true north zero position information sent by the radar main system, including:

[0055] The true north zero position information sent down in real time by the radar main system, or the true north zero position information last sent down by the radar main system and stored by the turntable control board before power-on.

[0056] Exemplarily, the radar main system obtains the true north zero position information reported by the north-seeking gyroscope, and then sends it to the turntable control board.

[0057] It should be noted that the true north zero position information obtained by the turntable control board is floating point data of 0° to 360° and needs to be converted into binary, including:

[0058] According to the following formula, the floating point true north zero position information of 0° to 360° is converted into 32-bit binary true north zero position information as the original binary;

[0059] pos_int=(Uint32)((zeor_int)*((2 n -1) / 360)) formula (1)

[0060] Among them, zeor_int represents the floating-point true north zero position information of 0° to 360°, n represents the number of valid bits of data of the absolute encoder, and Uint32 represents the true north zero position information converted into 32-bit binary.

[0061] According to the number of valid bits n of the data of the absolute encoder, the lower n bits of the original binary are taken as the binary true north zero position information.

[0062] Exemplarily, the number of valid data bits of the hexadecimal encoder is n=16, zeor_int is 90°, then pos_int=000000000000000001000000000000000, and the lower 16 bits are taken to obtain the converted true north zero position information zero_data[15:0]=01000000000000000.

[0063] Subtract the binary true north zero position information from the binary position information to obtain the relative azimuth signal.

[0064] Furthermore, when the azimuth signal relative to the zero position of true north is 0, it indicates that the current azimuth points to the zero position of true north. In order to ensure the accuracy of the output time and the signal accuracy, the main clock rising edge is designed to trigger the turntable control board to output the ARP signal. The timer output pulse width can be designed according to the requirements of the radar main system.

[0065] Specifically, considering that the turntable can rotate forward and reverse, when the relative orientation signal is 0, any one of the following conditions can be met:

[0066] The upper two bits of the relative position signal of the previous sampling period are 00, and the upper two bits of the relative position signal of the current sampling period are 11;

[0067] or,

[0068] The upper two bits of the relative position signal of the previous sampling cycle are 11, and the upper two bits of the relative position signal of the current sampling cycle are 00.

[0069] Set the previous state of the relative azimuth signal to t_fw_data, and the current state of the relative azimuth signal to fw_data, then the program code corresponding to the above conditions can be expressed as: ((t_fw_data[n-1:n-2]==2'b00)&&(fw_data[n-1:n-2]==2'b11))||((t_fw_data[n-1:n-2]==2'b11)&&(fw_data[n-1:n-2]==2'b00)).

[0070] Exemplarily, the turntable control board obtains and converts the true north zero position information zero_data[15:0]=01000000000000000. When the turntable is at the true north zero position, the binary position information collected in two adjacent sampling periods is 0011111111111111 and 01000000000000000 respectively. After subtracting them respectively, the relative orientation signal t_fw_data[15:0]=1111111111111111 of the previous sampling period is obtained, and the relative orientation signal fw_data[15:0]=0000 0000 0000 0000 of the current sampling period is obtained. At this time, the conditions of (t_fw_data[n-1:n-2]==2'b11)&&(fw_data[n-1:n-2]==2'b00) are met, and the ARP signal is output.

[0071] S13: When the turntable speed is not 0, according to the accuracy of the ACP signal sent by the radar main system and the length of the binary position information, the level signal at the corresponding bit is taken out from the relative azimuth signal as the ACP signal output.

[0072] It should be noted that the accuracy of the ACP signal sent by the radar main system is less than the length of the binary position information.

[0073] The number of A / B pulses output by the existing incremental encoder in one circle is 2n, while the data of the absolute encoder is binary, and the maximum value is 2n-1. For example, when n is equal to 16, the maximum position value of the absolute encoder is 11111111111111111. After one rotation, the relative position signal fw_data[15:0] changes from 0000000000000000 to 111111111111111111. The highest bit fw_data

[15] has only one high pulse of 20, the second highest bit fw_data

[14] has two high pulses of 21, the third highest bit fw_data

[13] has four high pulses of 23, and so on. The lowest bit fw_data[0] has 32768 high pulses of 215. Therefore, when the hexadecimal absolute encoder is assembled, the maximum accuracy of the ACP signal is 15.

[0074] According to the ACP signal accuracy m sent by the radar main system and the length n of the binary position information, the level signal is taken out from the relative azimuth signal as the ACP signal output, that is, the nm-th level signal in the relative azimuth signal is output as the ACP signal.

[0075] For example, when a hexadecimal absolute encoder n=16 is assembled, if m=15, the first-bit level signal fw_data[0] in the relative orientation signal is output as the ACP signal, meeting the 15-bit ACP signal accuracy requirement; if m=14, the second-bit level signal fw_data[1] in the relative orientation signal is output as the ACP signal, meeting the 14-bit ACP signal accuracy requirement.

[0076] When using an incremental encoder, the ACP signal accuracy is generally the encoder resolution. When adjusting the ACP signal accuracy, since the radar main system determines the direction of the turntable movement based on the A / B phase relationship, two counter programs must be written to read the A / B phase pulses, which places high requirements on the logic timing of the counter program. When using an absolute encoder, the radar main system directly uses the turntable direction uploaded by the turntable control board as the basis for the radar main system to determine the direction of antenna rotation; when the turntable control board receives the instruction to adjust the ACP signal accuracy mode issued by the radar main system, it can easily output the ACP signal according to the adjusted accuracy. The algorithm is simple, which improves the applicability of the turntable.

[0077] S14: The turntable control board periodically uploads the turntable speed and turntable direction to the radar main system.

[0078] It should be noted that the turntable control board program sets a timer, for example, every 50ms, it periodically uploads real-time motion status information to the radar main system, including the turntable self-test status mark, position information, turntable speed and turntable direction.

[0079] Preferably, the radar main system updates the radar antenna position according to the received turntable direction and ACP and ARP signals, including:

[0080] When the radar main system receives an ACP signal, if the turntable is in the forward direction, the current position of the radar antenna is adjusted by +360° / 2 m ; If the turntable direction is reverse, the radar antenna current position -360° / 2 m , where m represents the ACP signal accuracy;

[0081] Every time the radar main system receives an ARP signal, the current position of the radar antenna is updated to 0°.

[0082] Compared with the prior art, the method for outputting ACP and ARP signals based on an absolute encoder provided in this embodiment realizes the function of outputting ACP and ARP signals of a radar antenna turntable equipped with an absolute encoder, and removes the restriction that only an incremental encoder can be selected when the radar antenna system requires the turntable to send ACP and ARP signals. It can be widely used in radar antenna turntable equipment, so that it can not only output the ACP and ARP signals required by the radar main system, but also continue to have the advantages of the absolute encoder, such as compact structure, strong anti-interference ability, and power-off memory function, and the ACP signal accuracy is optional, the algorithm is simple, and the applicability of the turntable is improved.

[0083] Example 2

[0084] Another embodiment of the present invention discloses a system for outputting ACP and ARP signals based on an absolute encoder, thereby realizing the method for outputting ACP and ARP signals in Embodiment 1. The specific implementation of each component refers to the corresponding description in Embodiment 1. The system includes an absolute encoder, a turntable control panel and a radar main system; wherein,

[0085] Absolute encoder, used to communicate with the turntable control board and send binary position information;

[0086] The turntable control board is used to communicate with the absolute encoder and the radar main system. After power-on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction; the turntable control board obtains the true north zero position information sent by the radar main system, subtracts the binary true north zero position information from the binary position information, and obtains the relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output the ARP signal; when the turntable speed is not 0, according to the ACP signal accuracy sent by the radar main system and the length of the binary position information, the level signal on the corresponding position is taken out from the relative azimuth signal as the ACP signal output; the turntable control board periodically uploads the turntable speed and turntable direction to the radar main system;

[0087] The radar main system is used to send the true north zero position information or ACP signal accuracy to the turntable control board; update the radar antenna position according to the received turntable direction and ACP and ARP signals.

[0088] like Figure 2 As shown in FIG. 1 , a hardware structure example diagram of a system for outputting ACP signals and ARP signals based on absolute encoder information is provided. Figure 2 The main architecture of the turntable control board is embedded DSP+FPGA, which has the characteristics of high main frequency, fast signal acquisition and processing rate, etc. The control board mainly includes the voltage conversion chip and corresponding peripheral circuits, the communication interface chip and corresponding peripheral circuits, the level conversion isolation chip and corresponding peripheral circuits, the FPGA chip and its configurator and corresponding peripheral circuits, the DSP chip and its storage flash chip and corresponding peripheral circuits.

[0089] It should be noted that the main architecture of the turntable control board is not limited to the DSP+FPGA architecture, but also includes other signal processors + programmable logic device architectures that can execute instructions and perform arithmetic and logical operations, such as MCU+FPGA architecture, DSP+CPLD architecture, MCU+CPLD architecture, ARM+FPGA architecture, ARM+CPLD architecture, etc.

[0090] Specifically, the voltage converter chip in the turntable control board is used to provide matching power for each chip, including +5V to +3.3V, +5V to +1.2V and +5V chips. The +5V chip can provide power supply voltage for the encoder, the +5V to +3.3V converter chip provides power supply voltage for the DSP chip and FPGA chip, and the +5V to +1.2V converter chip provides core voltage for the IP core of the FPGA chip. When the system power supply voltage is not +5V, other voltage converter chips can be used to meet the control board usage requirements, or even an external voltage converter power module.

[0091] Since the high-level voltage of the DSP and FPGA signals sent and received must be consistent with the power supply voltage of 3.3V, and the high-level voltage of the signal on the transmission route is generally 5V, a level conversion isolation chip is used to match the signal voltage of the main architecture chip and the signal voltage on the transmission route. The level conversion isolation chip is not limited to the SN74ALVC164245DGGR.

[0092] The communication interface chip is the bridge between the turntable control board and the absolute encoder and radar main system. It is not limited to the use of high-speed differential line drivers such as the low-power RS-485 / RS-422 transceiver MAX490EESA. Other interface chips such as Ethernet interface can also be used, which is determined by the communication method required by the user. Considering the transmission distance and effectiveness of the signal, the turntable control board and the radar main system communicate using RS422 transmission mode, and the selected absolute position encoder also uses RS422 communication mode.

[0093] The FPGA chip communicates with the absolute encoder through the communication interface chip and the level conversion isolation chip, reads the binary position information and sends it to the DSP chip, receives the ACP signal accuracy information and true north zero position information from the DSP chip, and outputs the corresponding ACP signal and ARP signal to the radar main system.

[0094] The DSP chip communicates with the radar main system through the communication interface chip and the level conversion isolation chip, receives the ACP signal accuracy information and the true north zero position information, stores the processed data in the flash chip through the SPI interface and sends it to the FPGA chip, and uploads the turntable motion status information to the radar main system in real time.

[0095] Since the system of the present embodiment based on the output of ACP and ARP signals by the absolute encoder can refer to the above method in relation to each other, it is a repeated description here, so it will not be repeated here. Since the principle of the present system embodiment is the same as that of the above method embodiment, the present system also has the corresponding technical effects of the above method embodiment.

[0096] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for outputting ACP and ARP signals based on an absolute encoder, characterized in that: The steps include: After power-on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction; the length of the binary position information is consistent with the number of valid bits n of the data of the absolute encoder; The calculation of the turntable speed and turntable direction includes: converting the binary position information collected each time into floating point data of 0° to 360°, and then multiplying it by the resolution of the absolute encoder to obtain the position value to be calculated; dividing the difference between the position values ​​to be calculated collected twice adjacently by the sampling period to obtain the turntable speed; when the turntable speed is a positive value, the turntable direction is forward rotation; when the turntable speed is a negative value, the turntable direction is reverse rotation; The turntable control board obtains the true north zero position information sent by the radar main system, subtracts the true north zero position information converted into binary from the binary position information, and obtains a relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output an ARP signal; When the turntable speed is not 0, according to the accuracy of the ACP signal sent by the radar main system and the length of the binary position information, the level signal at the corresponding bit is taken out from the relative azimuth signal as the ACP signal output; The turntable control board periodically uploads the turntable speed and direction to the radar main system.

2. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 1, characterized in that: The method further includes: the radar main system updates the radar antenna position according to the received turntable direction and the ACP and ARP signals.

3. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 2, characterized in that: The obtaining of the true north zero position information sent by the radar main system includes: the true north zero position information sent by the radar main system in real time, or the true north zero position information last sent by the radar main system and stored in the turntable control board before power-on.

4. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 3, characterized in that: The true north zero position information converted into binary includes: The turntable control board converts the acquired floating point true north zero position information of 0° to 360° into 32-bit binary true north zero position information as the original binary; According to the number of valid bits n of the data of the absolute encoder, the lower n bits of the original binary are taken as the binary true north zero position information.

5. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 1, characterized in that: When the relative position signal is 0, any one of the following conditions is met: The upper two bits of the relative position signal of the previous sampling period are 00, and the upper two bits of the relative position signal of the current sampling period are 11; or, The upper two bits of the relative position signal of the previous sampling cycle are 11, and the upper two bits of the relative position signal of the current sampling cycle are 00.

6. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 1, characterized in that: The accuracy of the ACP signal sent by the radar main system is less than the length of the binary position information.

7. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 6, characterized in that: According to the ACP signal accuracy m sent by the radar main system and the length n of the binary position information, the level signal at the corresponding bit is taken out from the relative azimuth signal and output as the ACP signal, that is, the nm-th bit level signal in the relative azimuth signal is output as the ACP signal.

8. The method for outputting ACP and ARP signals based on an absolute encoder according to claim 2, characterized in that: The radar main system updates the radar antenna position according to the received turntable direction and ACP and ARP signals, including: When the radar main system receives an ACP signal, if the turntable is in the forward direction, the current position of the radar antenna is adjusted by +360° / 2 m ; If the turntable direction is reverse, the current position of the radar antenna is -360° / 2 m , where m represents the ACP signal accuracy; Every time the radar main system receives an ARP signal, the current position of the radar antenna is updated to 0°.

9. A system based on an absolute encoder outputting ACP and ARP signals, characterized in that: include: Absolute encoder, turntable control panel and radar main system; among them, An absolute encoder is used to communicate with the turntable control board and send binary position information; the length of the binary position information is consistent with the number of valid bits n of the data of the absolute encoder; The turntable control board is used to communicate with the absolute encoder and the radar main system. After power-on, the turntable control board communicates with the absolute encoder according to the sampling period, collects binary position information, and calculates the turntable speed and turntable direction, including: converting the binary position information collected each time into floating-point data of 0° to 360°, and then multiplying it by the resolution of the absolute encoder to obtain the position value to be calculated; dividing the difference between the position values ​​to be calculated collected twice adjacently by the sampling period to obtain the turntable speed; when the turntable speed is a positive value, the turntable direction is forward rotation; when the turntable speed is a negative value, the turntable is reverse rotation. The direction is reverse; the turntable control board obtains the true north zero position information sent by the radar main system, subtracts the true north zero position information converted into binary from the binary position information, and obtains a relative azimuth signal; when the relative azimuth signal is 0, the rising edge triggers the turntable control board to output an ARP signal; when the turntable speed is not 0, according to the ACP signal accuracy sent by the radar main system and the length of the binary position information, the level signal on the corresponding bit is taken from the relative azimuth signal as an ACP signal output; the turntable control board periodically uploads the turntable speed and turntable direction to the radar main system; The radar main system is used to send the true north zero position information or ACP signal accuracy to the turntable control board; update the radar antenna position according to the received turntable direction and ACP and ARP signals.

Images