Surveying and mapping data return method and device

Abstract

The invention provides a surveying and mapping data return method and device which are used in the technical field of communication, and the method comprises the steps: obtaining engineering surveying and mapping data; engineering surveying and mapping data are compressed through an LZMA lossless compression algorithm and differential coding, and the compressed engineering surveying and mapping data are fragmented based on a data packet fragmentation technology; encrypting the fragmented engineering surveying and mapping data through a hardware encryption chip and a CRC check code; transmitting the encrypted engineering surveying and mapping data through an RDSS service based on an adaptive transmission protocol according to the Beidou signal strength, and dynamically adjusting the data transmission rate by the adaptive transmission protocol according to the Beidou signal strength; and obtaining the fragments which are fed back by the receiving end and are marked to be failed in transmission, and carrying out breakpoint resume on the fragments which are failed in transmission. According to the scheme, efficient and reliable return of unmanned area surveying and mapping data is realized based on the Beidou RDSS, and the problems of limited surveying and mapping range, complicated operation, high operation cost and the like in the traditional RTK technology are avoided.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a method and device for transmitting mapping data back. Background Art

[0002] With the economic development and technological progress, the requirements for the safety and stability of structures in engineering and architectural surveys are becoming increasingly stringent, and high-precision measurement has become a rigid demand in the industry. Real-time kinematic (RTK) technology, which can provide centimeter-level positioning accuracy (much higher than traditional optical measurement methods), is widely used in the field of engineering surveying. However, traditional RTK technology relies on the Internet or line-of-sight wireless communication links to obtain GPS differential signals, and there are significant technical bottlenecks in special areas without public network coverage such as deserts, plateaus, and oceans.

[0003] Traditional RTK technology relies on a line-of-sight wireless communication link between a base station and a mobile station to transmit differential signals. Its typical implementation method is as follows: (1) Base station deployment, a fixed base station is set up at the engineering site, which consists of a high-precision GPS receiver, a data processing computer, and a radio transmitter. The base station needs to be installed at a stable location with good line-of-sight conditions, and the original satellite observation data (carrier phase, pseudorange, etc.) is obtained through the GPS receiver; (2) Data transmission link, the base station computer generates differential corrections through RTK calculation software and sends them to the mobile station through a UHF / VHF radio module. The mobile station receives the differential signal and fuses it with its own GPS observation data to achieve centimeter-level positioning (typical communication distance ≤ 10 km); (3) Mobile station operation, the mobile station needs to carry a GPS receiver, a radio receiver, and a handheld terminal, and move and operate in the measurement area. The measurement results depend on the line-of-sight communication between the base station and the mobile station and are easily affected by terrain occlusion or electromagnetic interference.

[0004] Obviously, traditional RTK technology relies on a line-of-sight wireless communication link between a base station and a mobile station to transmit differential signals. A fixed base station is deployed in the measurement area, satellite observation data is obtained through a GPS receiver, differential corrections are generated through computer calculation, and the differential data is sent to the mobile station through a UHF / VHF radio module. The mobile station combines its own observations to achieve precise positioning. However, the above solution has serious limitations in areas without public network coverage such as deserts, plateaus, and oceans. The radio communication distance is limited by power and terrain occlusion (usually ≤ 10 km), and the mapping range is limited; signal interruption occurs in harsh environments (such as sand and rainstorms), and the equipment needs to be reset frequently, making the operation cumbersome; the deployment of the base station depends on a stable power supply and manual maintenance, and the operation cost is extremely high. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method and device for transmitting mapping data back, which are used to solve the problems of limited mapping range, cumbersome operation, and high operation cost in the current data transmission based on RTK technology.

[0006] In the first aspect of the embodiments of the present invention, a method for transmitting surveying and mapping data is provided, including: Obtaining engineering surveying and mapping data; Compressing the engineering surveying and mapping data through the LZMA lossless compression algorithm and differential encoding, and fragmenting the compressed engineering surveying and mapping data based on the data packet fragmentation technology; Encrypting the fragmented engineering surveying and mapping data through a hardware encryption chip and a CRC check code; Transmitting the encrypted engineering surveying and mapping data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength, and the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength; Obtaining the fragments marked as transmission failures feedback by the receiving end, and performing breakpoint resumption transmission on the failed transmission fragments.

[0007] In the second aspect of the embodiments of the present invention, a device for transmitting surveying and mapping data is provided, including: An acquisition and obtaining module, configured to obtain engineering surveying and mapping data; A data preprocessing module, configured to compress the engineering surveying and mapping data through the LZMA lossless compression algorithm and differential encoding, and fragment the compressed engineering surveying and mapping data based on the data packet fragmentation technology; and encrypt the fragmented engineering surveying and mapping data through a hardware encryption chip and a CRC check code; A Beidou communication module, configured to transmit the encrypted engineering surveying and mapping data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength, and the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength; A data retransmission module, configured to obtain the fragments marked as transmission failures feedback by the receiving end, and perform breakpoint resumption transmission on the failed transmission fragments.

[0008] A power supply module, configured to supply power to the acquisition and obtaining module, the data preprocessing module, the Beidou communication module, and the data retransmission module.

[0009] In the third aspect of the embodiments of the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method described in the first aspect of the embodiments of the present invention are implemented.

[0010] In the fourth aspect of the embodiments of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method provided in the first aspect of the embodiments of the present invention are implemented.

[0011] In the embodiments of the present invention, based on the Beidou RDSS service, by fragmenting, compressing, encrypting, and verifying the surveying and mapping data and transmitting it based on an adaptive transmission protocol, the efficient and reliable transmission of surveying and mapping data in uninhabited areas can be achieved, effectively expanding the surveying and mapping scope and avoiding the problems of cumbersome operations and high operation costs caused by the traditional RTK technology. Through fragmenting and compressing, the effective payload of a single message can be maximized while ensuring data integrity; based on the adaptive transmission protocol, the transmission frequency can be dynamically optimized according to the Beidou signal strength, reducing power consumption; by using a hardware encryption chip and CRC verification, data tampering can be prevented and communication security can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 It is a schematic flowchart of a method for transmitting surveying and mapping data provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a device for transmitting surveying and mapping data provided by an embodiment of the present invention; Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the following described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0015] It should be understood that the term "including" and other similar expressions in the specification or claims of the present invention and the above drawings mean covering non-exclusive inclusion. For example, a process, method, system, or device including a series of steps or units is not limited to the listed steps or units. In addition, "first" and "second" are used to distinguish different objects and are not used to describe a specific order.

[0016] Please refer to Figure 1 , a schematic flowchart of a method for transmitting surveying and mapping data provided by an embodiment of the present invention, includes: S101. Obtain engineering surveying and mapping data; The engineering surveying and mapping data refers to the graphic and position-related data reflecting the current ground situation obtained through measurement based on existing feature points and boundaries on the ground. Generally, it can include plane control data, elevation control data, topographic map data, lofting calibration data, etc. In this embodiment, it can refer to the RTK coordinate sequence.

[0017] S102. Compress the engineering surveying and mapping data through the LZMA lossless compression algorithm and differential encoding, and fragment the compressed engineering surveying and mapping data based on the data packet fragmentation technology; The LZMA (Lempel-Ziv-Markov chain Algorithm) lossless compression algorithm is an algorithm used for lossless data compression, which has the characteristics of high compression ratio, variable dictionary size, and fast compression speed, and is convenient for application in embedded devices. Differential encoding is an encoding method in which, except for the first element in the data stream, the remaining elements are all represented as the difference between each element and the previous element. By quantifying the difference value, the quantization error can be effectively reduced and the data content can be compressed at the same code rate.

[0018] Exemplarily, aiming at the single-packet capacity limit of Beidou short message (≤1000 bytes), a deeply customized LZMA lossless compression algorithm is adopted. By setting a streamlined dictionary (such as 32KB, adapted to the ARM Cortex-M4 embedded processor), enabling the medium compression level and the "micro-data mode" for triple optimization, the original RTK coordinate sequence (including longitude, latitude, elevation, and timestamp) is compressed to 60%-70% of the original volume; by using differential encoding, the first point coordinate retains the WGS-84 absolute accuracy (0.1mm level, 32-bit floating-point storage), and the subsequent points are converted into three-dimensional Δ values (ΔX, ΔY, ΔZ) with an accuracy of 1mm, represented by 16-bit signed integers, and run-length encoding is implemented for consecutive identical Δ values (such as "ΔX = 0 for 10 consecutive times" encoded as 0x00 0x0A), which can reduce the volume of coordinate data to 20%-30% of the original. After combining with LZMA compression, the comprehensive compression rate breaks through 80%.

[0019] By performing LZMA lossless compression algorithm and differential encoding on the compression of engineering surveying and mapping data, the data volume can be greatly reduced, meeting the communication requirements of Beidou short message and improving the data transmission efficiency.

[0020] Data packet fragmentation refers to the need to split data packets into multiple data packets for transmission due to the maximum transmission unit limit of the data link layer in network communication. In this embodiment, the data to be pre-transmitted is split into fragmented data packets of the same size for transmission. The fragmented data packets include a protocol header and a data block, and both the protocol header and the data block are of a fixed size in bytes.

[0021] Preferably, set the protocol header of each shard to the first number of bytes and the data block to the second number of bytes; perform data allocation on the data blocks through a dynamic capacity allocation algorithm.

[0022] In one embodiment, each shard contains a 10-byte protocol header and a 550-byte data block. The protocol header contains the shard identifier 0xBEAC, a 24-bit sequence number, a shard type flag, a compression / encryption status code, and an extended reserved field. Through the dynamic capacity allocation algorithm, the total size is strictly limited to 560 bytes (including a 4-byte CRC-32 checksum). The dynamic capacity allocation algorithm is similar to the dynamic memory allocation algorithm and is used for data allocation to balance resource utilization and system performance. It mainly includes the first-fit algorithm, the best-fit algorithm, the circular first-fit algorithm, etc. The selection of the allocation algorithm needs to combine the request characteristics of the actual scenario.

[0023] S103. Encrypt the sharded engineering surveying and mapping data through a hardware encryption chip and a CRC checksum. The hardware encryption chip is a hardware component specifically designed to protect data security. Its core is to implement data encryption through built-in encryption algorithms and hardware-level security mechanisms. In this embodiment, the domestic SGM7046 encryption chip (supporting the SM4-CBC / CTR dual mode) is used at the hardware layer to encrypt the sharded data blocks with a 128-bit key.

[0024] Among them, the SM4-CBC national encryption algorithm is integrated in the hardware encryption chip.

[0025] The SM4-CBC national encryption algorithm is an encryption scheme combining the block cipher algorithm SM4 and the CBC (Cipher Block Chaining) mode. The same plaintext generates different ciphertexts after encryption, which can avoid the plaintext mode leakage problem of the ECB mode and can be calculated in parallel during decryption.

[0026] Dynamically create an initialization vector (IV) through the TRNG true random number generator built in the hardware encryption chip, and perform a composite operation with the dynamic session key in the protocol header to obtain the encrypted data. The session key is generated by the ECDH algorithm (key update period: 30 minutes ± 5% jitter). The composite operation includes XOR (exclusive OR operation) and rotation shift. Encryption through the hardware chip can resist replay attacks and brute force cracking.

[0027] The CRC (Cyclic Redundancy Check) checksum, that is, the cyclic redundancy checksum, realizes the cyclic check between the valid information and the check bits through a certain mathematical operation. The shard-level CRC check covers the protocol header and the data block. Using the improved polynomial 0xEDB88320 (the generation matrix is optimized for 64-bit parallel calculation) can achieve burst error detection (it can correct ≤ 32-bit consecutive errors).

[0028] S104. Transmit the encrypted engineering surveying and mapping data through the RDSS service based on the Beidou signal strength using an adaptive transmission protocol, where the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength. The adaptive transmission protocol is a technology that dynamically adjusts the transmission strategy according to the network environment, and it can dynamically adjust the data transmission rate according to the Beidou signal strength. The RDSS (radio determination satellite system) service is the satellite radio determination service. It can measure parameters such as the coordinates (position), moving speed, and direction of a moving target through the radio wave propagation time between the satellite and the moving target, and can transmit short messages, that is, the short message service. The Beidou RDSS communication protocol complies with GB / T 30287-2013 "Beidou Satellite Navigation System Short Message Communication Protocol".

[0029] Among them, based on the real-time monitoring of the strength and bit error rate of the Beidou signal, a signal quality assessment level is constructed, and the data sending interval and Turbo coding rate are set in different levels. Real-time solve the ionospheric disturbance parameters through the Klobuchar model. According to the ionospheric disturbance parameters, predict the channel attenuation trend, and switch the QPSK / BPSK modulation mode in advance.

[0030] The adaptive transmission protocol can achieve highly reliable transmission of Beidou short messages in a complex channel environment through multi-modal dynamic regulation. Based on the real-time monitoring of the signal strength (RSSI resolution ±0.5dBm, sampling frequency 10Hz) and bit error rate (BER) by the Beidou RDSS module, a signal quality assessment level is constructed, such as a strong signal area, a medium signal area, and a weak signal area. The data sending interval and Turbo coding rate are set in different levels. Exemplarily, in the strong signal area (RSSI≥-130dBm), the minimum sending interval of 1 second / packet and the Turbo coding rate of 3 / 4 (effective rate 420bps) are enabled; in the medium signal area (-135dBm≤RSSI<-130dBm), it is dynamically switched to 2 seconds / packet + Turbo 1 / 2 rate; in the weak signal area (RSSI<-135dBm), an adaptive interval (2-10 seconds / packet, step size 2 seconds) and Turbo 1 / 3 rate (redundancy increased to 67%) are adopted.

[0031] Real-time solve the ionospheric disturbance parameters (such as the total electron content TEC value, accuracy ±3TECU) through the Klobuchar model. According to the ionospheric disturbance parameters, predict the channel attenuation trend, and pre-emptively switch the QPSK / BPSK modulation mode (the BER sensitive threshold can be set to 10^-4).

[0032] S105. Obtain the shards marked as transmission failures feedback by the receiving end, and perform breakpoint resumption transmission on the shards with failed transmissions.

[0033] Breakpoint resuming means that when the transmission of a fragmented data packet fails, the receiving end marks the fragment that failed to be transmitted and retransmits it according to the fragment sequence number. After successfully receiving the fragmented data, the receiving end will decrypt, decompress and perform CRC verification on the fragmented data. If the verification is successful, it will be merged to generate complete mapping data. If the verification fails, the failed fragment will be marked and retransmission will be requested.

[0034] In this embodiment, based on the Beidou RDSS service, reliable feedback of surveying and mapping data in uninhabited areas can be achieved through slicing compression, encryption verification and adaptive transmission of surveying and mapping data, avoiding the problems of limited surveying and mapping range, cumbersome operation and high operating cost of traditional data feedback based on RTK technology.

[0035] This embodiment breaks through the limitations of the geographical environment. Traditional surveying and mapping data backhaul relies on 4G / 5G networks or relay radio stations, and there are coverage blind spots in uninhabited areas, oceans and other areas without base stations. By adopting the Beidou RDSS module, full coverage is achieved through synchronous orbit satellites, and a transmission success rate of 97.3% can be maintained in an environment without public network coverage. The adaptive Turbo coding technology dynamically adjusts the coding efficiency according to the ionospheric disturbance, and reduces the bit error rate by 42% compared with the fixed coding scheme, solving the signal attenuation problem of traditional satellite communications under complex meteorological conditions; the transmission efficiency is improved, and data segmentation compression technology is developed to address the length limit of 560 bytes / time for Beidou short messages. After the original surveying and mapping data is losslessly compressed by LZMA, differential coding based on the characteristics of surveying and mapping data is adopted, which can increase the amount of data transmitted in a single time by 3.8 times.

[0036] In one embodiment, when the mapping data exceeds a preset limit value after compression, a secondary sharding mechanism is triggered to split the data blocks in each shard for a second time, and a serial number cycle strategy is used to allocate shard serial numbers.

[0037] Secondary sharding is the process of sharding already sharded data again. When the compressed data exceeds the limit, the secondary sharding mechanism is automatically triggered to split the sharded data block into multiple sub-shards, and adopt a serial number recycling strategy to avoid long-term transmission overflow, such as timestamp-based serial number generation, lock-based serial number generation, etc.

[0038] In one embodiment, before step S102, the method further includes: Set up a dynamic dictionary switching mechanism to automatically enable Huffman coding compensation when the compression rate is lower than 50%; set up an extreme compression mode, turn off differential coding in the extreme compression mode, and lower the accuracy of the surveyed points; reserve fields in the protocol header in the fragment to support the embedding of satellite emergency commands.

[0039] Design a dynamic dictionary switching mechanism. When the shard compression ratio is lower than 50%, automatically enable Huffman coding compensation, set the extreme compression mode, temporarily turn off differential coding and relax the point position accuracy to ensure deep compatibility with the Beidou protocol stack. The protocol encapsulation strictly follows the Beidou short message payload area division (user data area 560 bytes + protocol extension area 40 bytes), and the reserved field at the shard header supports the embedding of satellite emergency instructions. This embodiment can fully guarantee the communication reliability in areas without network coverage and extreme environments.

[0040] In one embodiment, perform resume from breakpoint based on the incremental shard status table and dual-channel ACK / NACK feedback, and preferentially retransmit the shard data with abnormal sequence numbers.

[0041] The resume from breakpoint mechanism adopts an incremental shard status table (storage capacity ≥ 1,000,000 records, hash index response time < 1 ms) and dual-channel ACK / NACK feedback (main channel Beidou short message + auxiliary channel LoRa redundant broadcast, dual-link redundancy ≥ 99.9%). After the signal is restored, preferentially retransmit the shards with abnormal sequence numbers, and clear the timeout records based on the LRU algorithm, and cooperate with the sliding window protocol to achieve the balance of channel utilization and reliability.

[0042] In this example, performing resume from breakpoint based on the incremental shard status table and dual-channel ACK / NACK feedback can guarantee the real-time performance and reliability of communication. Actual measurements show that in the extremely weak signal of -140 dBm on the Tibetan Plateau, the protocol stabilizes the daily effective data transmission volume at 18.4 MB (average throughput 213 B / s) through dynamic speed reduction (2 seconds per packet) and coding enhancement (Turbo 1 / 3 code rate), which is 6.3 times higher than the fixed parameter scheme. The bit error rate is controlled at the order of 10^-5 (measured BER = 2.3×10^-5), and the retransmission rate is lower than 0.7%.

[0043] It should be understood that the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0044] Figure 2 The following is a schematic structural diagram of a mapping data feedback device provided by an embodiment of the present invention. The device includes: An acquisition and obtaining module 210, used to obtain engineering mapping data; The acquisition module 210 may be composed of a high-precision GPS sensor (model UBLOX ZED-F9P) and an ARM Cortex-M4 processor, and is connected through the I2C bus; The data preprocessing module 220 is used to compress engineering surveying and mapping data through the LZMA lossless compression algorithm and differential coding, and fragment the compressed data based on the data packet fragmentation technology; and encrypt the fragmented engineering surveying and mapping data through a hardware encryption chip and CRC check codes. The data preprocessing module 220 may include an FPGA chip (model Xilinx Spartan-6 LX45) integrating the LZMA compression algorithm, which communicates with the acquisition module 210 through a PCIe interface. The internal logic circuit of the data preprocessing module 220 may include: Compression unit: Integrating the LZMA algorithm hardware acceleration core (for example, dictionary size 32KB, compression level 5) and differential coding, receiving the original data (bandwidth 2.5Gbps) of the ARM processor through a PCIe x1 interface. Fragmentation unit: Adopting the first-fit dynamic memory allocation algorithm to split the compressed data into fragments (for example, fragments of 560 bytes, protocol header 10 bytes + data block 550 bytes). The protocol header may include a fragment identifier 0xBEAC, a 24-bit cyclic sequence number (for example, range 0x000000 - 0xFFFFFF), and a CRC-32 check code (polynomial 0xEDB88320), etc. Encryption unit: Connecting to the SGM7046 hardware encryption chip through an SPI interface to perform algorithm encryption (the 128-bit session key is generated by the ECDH protocol, and the key update period is 30 minutes ± 5% jitter).

[0045] Among them, the fragmentation of the compressed data based on the data packet fragmentation technology includes: Setting the protocol header of each fragment to the first number of bytes and the data block to the second number of bytes. Performing data allocation on the data block through a dynamic capacity allocation algorithm.

[0046] Optionally, the data preprocessing module 220 further includes: Secondary fragmentation unit, used to trigger the secondary fragmentation mechanism to split the data blocks in each fragment when the surveying and mapping data after compression exceeds a preset limit value, and adopt a serial number cycling strategy for fragment serial number allocation.

[0047] Among them, the hardware encryption chip integrates the SM4-CBC national encryption algorithm.

[0048] The Beidou communication module 230 is used to transmit the encrypted engineering surveying and mapping data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength. The adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength. The Beidou communication module 230 may include a Beidou RDSS communication circuit board (integrated with the UM220-IV chip of Huixin Telecom), which is connected to the SGM7046 hardware encryption chip, supports QPSK / BPSK modulation switching, and is connected to the FPGA through the SPI interface; Optionally, the transmission of the encrypted engineering surveying data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength includes: Based on the real-time monitoring of the strength and bit error rate of the Beidou signal, a signal quality assessment level is constructed, and the data transmission interval and Turbo coding rate are set in different levels; The ionospheric perturbation parameters are solved in real time through the Klobuchar model. According to the ionospheric perturbation parameters, the channel attenuation trend is predicted, and the QPSK / BPSK modulation mode is switched in advance.

[0049] The data retransmission module 240 is used to obtain the shards marked as transmission failures feedback by the receiving end, and perform breakpoint resumption transmission on the shards with failed transmissions.

[0050] The power supply module 250 is used to supply power to the acquisition and acquisition module, the data preprocessing module, the Beidou communication module, and the data retransmission module.

[0051] In one embodiment, before compressing the engineering surveying data through the LZMA lossless compression algorithm and differential coding, and fragmenting the compressed data based on the data packet fragmentation technology, it further includes: Set a dynamic dictionary switching mechanism to automatically enable Huffman coding compensation when the compression rate is lower than 50%; set an extreme compression mode, in which the differential coding is turned off and the point position accuracy of the surveying is lowered; Reserve fields in the protocol header part during fragmentation to support the embedding of satellite emergency instructions.

[0052] In one embodiment, the data retransmission module 240 includes: The breakpoint resumption transmission unit is used to perform breakpoint resumption transmission based on the incremental fragmentation status table and the dual-channel ACK / NACK feedback, and preferentially retransmit the shard data with abnormal sequence numbers.

[0053] The data retransmission module 240 is implemented based on an incremental fragmentation status table (storage capacity ≥ 1,000,000 records) and a dual-channel ACK / NACK feedback circuit (main channel Beidou short message + auxiliary channel LoRa module); In some embodiments, the power supply module 250 adopts a dual-mode power supply system and an intelligent wake-up mechanism. The dual-mode power supply system is powered by a photovoltaic-supercapacitor hybrid, and the intelligent wake-up mechanism is a LoRa-based remote wake-up mechanism. The photovoltaic input circuit supports a wide voltage input of 5-24V, and the MPPT efficiency is ≥97% (chip model LT8490); the supercapacitor bank is composed of 6 Maxwell 25F / 2.7V capacitors connected in series (total capacity 100F, energy storage 18kJ), and supports low-temperature startup at -40°C; when the photovoltaic input power < 1W, it automatically switches to supercapacitor power supply, and the endurance time is ≥428 hours (measured data).

[0054] This embodiment can operate all-weather. Cooperating with the remote wake-up module, the device can continuously work for 428 hours (measured data) when unattended. The power consumption in the sleep state is only 0.15W, saving 89% energy compared with the traditional continuous standby scheme. It is especially suitable for long-term field monitoring scenarios and can avoid the problem of high maintenance costs caused by relying on regular battery replacement.

[0055] In one embodiment, the surveying and mapping data transmission device adopts a triple protection mechanism of a main control FPGA, a standby MCU, and a hardware watchdog.

[0056] This embodiment can achieve multi-dimensional protection of system reliability. Through the three-mode redundant architecture and CRC check reinforcement, the reliability of the device is improved. Cooperating with the enhanced CRC-32 check algorithm, 99.9999% of burst errors can be detected. Combining with the automatic retransmission mechanism, data integrity transmission is still guaranteed under the harsh channel with a bit error rate of 10^-3, which can improve the reliability of the device.

[0057] It can be understood that in this embodiment, the device adopts a Beidou RDSS module to replace radio, constructs a dual-mode power supply circuit, and adopts a triple redundant architecture, which can avoid the problems of the communication module relying on line-of-sight transmission and the power supply module being single, and realize redundant design.

[0058] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described systems and modules can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0059] Figure 3 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. The electronic device is used for surveying and mapping data transmission. As Figure 3 shown, the electronic device 3 of this embodiment includes: a memory 310, a processor 320, and a system bus 330. The memory 310 includes a runnable program 3101 stored thereon. Those skilled in the art can understand, Figure 3The structure of the electronic device shown does not constitute a limitation on the electronic device, and it may include more or fewer components than shown, or combine certain components, or have a different component arrangement.

[0060] The following will specifically introduce each component of the electronic device in conjunction with Figure 3 : The memory 310 can be used to store software programs and modules. The processor 520 executes various functional applications and data processing of the electronic device by running the software programs and modules stored in the memory 510. The memory 310 mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the electronic device (such as cached data, etc.). In addition, the memory 310 can include high-speed random access memory and can also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0061] A runnable program 3101 containing an interface generation method is included in the memory 310. The runnable program 3101 can be divided into one or more modules / units. The one or more modules / units are stored in the memory 310 and are executed by the processor 320 to implement functions such as the transmission of mapping data based on Beidou short messages. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, and these instruction segments are used to describe the execution process of the runnable program 3101 in the electronic device 3. For example, the runnable program 3101 can be divided into functional modules such as an acquisition and obtaining module, a data preprocessing module, a Beidou communication module, and a data transmission module.

[0062] The processor 320 is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines. By running or executing the software programs and / or modules stored in the memory 310, and by calling the data stored in the memory 310, it executes various functions of the electronic device and processes data, thereby monitoring the overall state of the electronic device. Optionally, the processor 320 can include one or more processing units; preferably, the processor 320 can integrate an application processor and a modem processor. Among them, the application processor mainly processes the operating system, application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above modem processor may not be integrated into the processor 320.

[0063] The system bus 330 is used to connect the internal functional components of a computer and can transmit data information, address information, and control information. Its types can be, for example, PCI bus, ISA bus, CAN bus, etc. The instructions of the processor 320 are transmitted to the memory 310 through the bus, and the memory 310 feeds back data to the processor 320. The system bus 330 is responsible for the data and instruction interaction between the processor 320 and the memory 310. Of course, the system bus 330 can also be connected to other devices, such as network interfaces, display devices, etc.

[0064] In the embodiment of the present invention, the executable program executed by the processor 320 included in the electronic device includes: The obtained engineering surveying and mapping data; Compress the engineering surveying and mapping data through the LZMA lossless compression algorithm and differential coding, and fragment the compressed engineering surveying and mapping data based on the data packet fragmentation technology; Encrypt the fragmented engineering surveying and mapping data through a hardware encryption chip and CRC check code; Transmit the encrypted engineering surveying and mapping data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength, and the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength; Obtain the fragmented pieces marked as transmission failures feedback by the receiving end, and perform breakpoint resumption transmission on the fragmented pieces with failed transmission.

[0065] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0066] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] The above is the case. The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. A surveying and mapping data transmission method, characterized in that: include: Acquired engineering surveying and mapping data; The engineering surveying and mapping data is compressed by using the LZMA lossless compression algorithm and differential coding, and the compressed engineering surveying and mapping data is fragmented based on the data packet fragmentation technology; The engineering surveying and mapping data after slicing is encrypted through hardware encryption chip and CRC check code; According to the Beidou signal strength, the encrypted engineering surveying and mapping data is transmitted through the RDSS service based on the adaptive transmission protocol, and the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength; Obtain the fragments marked with transmission failures fed back by the receiving end, and perform breakpoint-resume transmission on the fragments that failed to be transmitted.

2. The method according to claim 1, characterized in that The fragmentation of compressed data based on the data packet fragmentation technology includes: Set the protocol header of each fragment to the first number of bytes and the data block to the second number of bytes; Data is allocated to data blocks through a dynamic capacity allocation algorithm.

3. The method according to claim 1, characterized in that The fragmentation of compressed data based on the data packet fragmentation technology also includes: When the mapping data exceeds the preset limit after compression, the secondary sharding mechanism is triggered to split the data blocks in each shard for a second time, and the serial number cycle strategy is used to allocate shard serial numbers.

4. The method according to claim 1, characterized in that: The hardware encryption chip integrates the SM4-CBC national encryption algorithm.

5. The method according to claim 1, characterized in that: Before compressing the engineering surveying and mapping data by using the LZMA lossless compression algorithm and differential coding and slicing the compressed engineering surveying and mapping data based on the data packet slicing technology, the method further includes: Set up a dynamic dictionary switching mechanism to automatically enable Huffman coding compensation when the compression rate is lower than 50%; Set the extreme compression mode, turn off the differential encoding in the extreme compression mode, and lower the point accuracy of the survey; The reserved fields in the protocol header in the fragment support the embedding of satellite emergency commands.

6. The method according to claim 1, characterized in that The transmitting of the encrypted engineering surveying and mapping data through the RDSS service based on the adaptive transmission protocol according to the Beidou signal strength includes: Based on real-time monitoring of Beidou signal strength and bit error rate, a signal quality evaluation level is established, and data transmission intervals and Turbo coding bit rates are set in different levels; The Klobuchar model is used to calculate the ionospheric disturbance parameters in real time. According to the ionospheric disturbance parameters, the channel attenuation trend is predicted and the QPSK / BPSK modulation mode is switched in advance.

7. The method according to claim 1, characterized in that The step of obtaining the fragments marked with transmission failures fed back by the receiving end and resuming the transmission of the fragments with failed transmissions comprises: Breakpoint retransmission is performed based on the incremental fragment status table and dual-channel ACK / NACK feedback, and fragment data with abnormal sequence numbers is retransmitted first.

8. A surveying and mapping data return device, characterized in that: include: Acquisition module, used to acquire engineering surveying and mapping data; A data preprocessing module is used to compress the engineering surveying and mapping data by using the LZMA lossless compression algorithm and differential coding, and to fragment the compressed engineering surveying and mapping data based on the data packet fragmentation technology; and to encrypt the fragmented engineering surveying and mapping data by using a hardware encryption chip and a CRC check code; Beidou communication module, used to transmit the encrypted engineering surveying and mapping data through RDSS service based on the adaptive transmission protocol according to the Beidou signal strength, and the adaptive transmission protocol dynamically adjusts the data transmission rate according to the Beidou signal strength; The data retransmission module is used to obtain the fragments marked with transmission failures fed back by the receiving end, and to resume the transmission of the fragments that failed to be transmitted; The power module is used to supply power to the acquisition module, data preprocessing module, Beidou communication module and data retransmission module.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of a surveying and mapping data return method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed, the steps of a surveying and mapping data return method as described in any one of claims 1 to 7 are implemented.

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