A kind of cascaded multi-channel ground penetrating radar high-speed real-time sampling device and sampling method

Abstract

An improved cascaded multi-channel ground-penetrating radar high-speed real-time sampling device includes two or more dual-channel high-speed real-time acquisition modules. Each module is equipped with a dual-transmit, dual-receive antenna unit. Clock synchronization signals and synchronization trigger signals are cascaded between the modules. Each module is connected to a router via a network. The sampling device disclosed in this invention features a modular design based on network communication, parameterized configuration, flexible cascading combinations, and high adaptability. Employing real-time high-speed sampling technology, it uses interleaved AD sampling technology to achieve a real-time sampling rate of tens of gigahertz through repeated transmission pulses, approaching the effect of real-time sampling.

Description

Technical Field

[0001] This invention belongs to the field of underground target detection by dedicated radar, and specifically relates to a high-speed real-time sampling device and sampling method for multi-channel ground-penetrating radar that integrates high-speed real-time sampling and multi-channel cascaded timing control. Background Technology

[0002] Ground-penetrating radar (GPR) can be widely used for non-destructive detection of concealed underground targets, especially in the survey and detection of hidden defects in urban roads and highways. Combined with video acquisition and positioning devices, it can effectively solve problems such as early warning of municipal road collapses, locating municipal pipeline networks, and conducting urban road maintenance surveys. Three-dimensional array GPR uses array antenna technology and multi-channel high-density scanning to acquire a three-dimensional image (three-dimensional slice) of a target area in a single scan, providing a clear and intuitive way to locate defects and facilitating subsequent data processing and intelligent identification. Traditional GPR based on equivalent sampling systems often requires hundreds or thousands of repeated transmission pulses to obtain echo data from a single channel. Combined with the repetition across multiple channels, this results in low detection efficiency, with typical operating speeds limited to only 10-20 km / h. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a cascaded multi-channel ground-penetrating radar high-speed real-time sampling device and sampling method, which can quickly build a high-speed three-dimensional array radar with a configurable number of channels under different detection scenarios.

[0004] The present invention adopts the following technical solution:

[0005] An improved cascaded multi-channel ground-penetrating radar high-speed real-time sampling device includes two or more dual-channel high-speed real-time acquisition modules. Each dual-channel high-speed real-time acquisition module is equipped with a dual-transmit and dual-receive antenna unit. Clock synchronization signals and synchronization trigger signals are cascaded between the dual-channel high-speed real-time acquisition modules. Each dual-channel high-speed real-time acquisition module is connected to a router via a network.

[0006] Furthermore, the dual-channel high-speed real-time acquisition module includes a central processing unit, a dual-channel trigger pulse delay unit, a dual-channel high-dynamic AD acquisition unit, and a multi-channel high-precision clock synchronization unit.

[0007] Furthermore, the central processing unit (CPU) receives control commands and transmits collected data to the outside world through the network. One CPU is set to master mode and the other CPUs are set to slave mode. The CPU in master mode generates the working timing of the entire sampling device and outputs a synchronization trigger signal to one of the CPUs in slave mode. The synchronization trigger signal is passed sequentially among the CPUs in slave mode.

[0008] The central processing unit controls the working repetition frequency of its dual-channel high-speed real-time acquisition module, outputs dual-channel transmit trigger pulses to dual-channel trigger pulse delay units, controls dual-channel high-dynamic AD acquisition units to acquire echo signals in a time-division manner, splices, superimposes, filters, and packages the acquired echo signals for external transmission.

[0009] Furthermore, the central processing unit is an FPGA processor.

[0010] Furthermore, the dual-path trigger pulse delay unit performs step-delay scanning and shaping amplification on the dual-path transmit trigger pulses and outputs them to the transmit antenna of the dual-transmit dual-receive antenna unit equipped in its dual-path high-speed real-time acquisition module.

[0011] Furthermore, the dual-path trigger pulse delay unit can generate a minimum 5ps dual-path sweep frequency transmission trigger signal.

[0012] Furthermore, the dual-channel high-dynamic AD acquisition unit acquires two analog signals in real time from the receiving antenna of the dual-transmitter dual-receiver antenna unit equipped in its dual-channel high-speed real-time acquisition module.

[0013] Furthermore, the dual-channel high-dynamic AD acquisition unit has a sampling rate of up to 2.5 GSPS and a minimum of 160 MSPS, with a sampling bit depth of 16 bits.

[0014] Furthermore, the multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module where the main working mode central processing unit is located generates a clock synchronization signal and outputs a clock synchronization signal to a multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module where the working mode central processing unit is located. The clock synchronization signal is transmitted sequentially between the multi-channel high-precision clock synchronization units of the dual-channel high-speed real-time acquisition module where the working mode central processing unit is located.

[0015] The multi-channel high-precision clock synchronization unit transmits the clock synchronization signal to the central processing unit, dual-channel trigger pulse delay unit, and dual-channel high-dynamic AD acquisition unit of the dual-channel high-speed real-time acquisition module to which it is located.

[0016] A sampling method applicable to the above-mentioned sampling device is improved in that: the central processing unit in the main working mode generates a synchronous trigger signal based on the trigger pulse of the ranging wheel, and transmits it sequentially to the central processing unit in the slave working mode. Based on this synchronous trigger signal, the echo data and synchronous GPS data of all dual-channel high-speed real-time acquisition modules are acquired. Each dual-channel high-speed real-time acquisition module generates a transmit trigger pulse and a receive trigger pulse in sequence. After traversing all transmit channels, the transmit trigger pulse is delayed by ΔT and then all transmit channels are traversed sequentially until the equivalent number of sampling times is completed, and the real-time sampling data of all transmit channels is acquired.

[0017] The beneficial effects of this invention are:

[0018] The sampling device disclosed in this invention features a modular design based on network communication, parameterized configuration, flexible cascading combinations, and high adaptability. It employs real-time high-speed sampling technology, using interleaved AD sampling to achieve a real-time sampling rate of tens of gigahertz through repeated transmission pulses, approaching the effect of real-time sampling. It also boasts strong scalability: the dual-channel high-dynamic AD acquisition unit can be equipped with chips of different rates and performance according to the antenna operating frequency, facilitating functional expansion and product diversification.

[0019] The sampling device disclosed in this invention provides a high-efficiency, convenient and fast cascading dual-channel high-speed real-time acquisition module. Through parameterized configuration and complex timing control, it can be cascaded into a high-speed three-dimensional array ground-penetrating radar system with any number of channels, so as to facilitate the convenient and rapid detection of underground target defects in environments such as sidewalks, urban roads, and highways.

[0020] The sampling method disclosed in this invention employs complex timing control technology and combines a one-transmit two-receive detection mode to achieve multi-channel array reception, thereby improving the efficiency of transmit and receive multiplexing. Attached Figure Description

[0021] Figure 1 This is a block diagram of the sampling device disclosed in this invention;

[0022] Figure 2 This is a block diagram of the dual-channel high-speed real-time acquisition module disclosed in this invention;

[0023] Figure 3 This is a timing diagram of the sampling method disclosed in this invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Example 1: This example discloses a cascaded multi-channel ground-penetrating radar high-speed real-time sampling device, such as... Figure 1 As shown, the system includes two or more dual-channel high-speed real-time acquisition modules, each equipped with a dual-transmit, dual-receive antenna unit, forming an independent structure. Each dual-channel high-speed real-time acquisition module has identical input and output interfaces, facilitating the combination and interconnection of multiple modules. A clock synchronization signal CLK and a synchronization trigger signal SYN are cascaded between the dual-channel high-speed real-time acquisition modules. Each dual-channel high-speed real-time acquisition module is connected to a router via a network, and can be operated and controlled through a single display and control software.

[0026] like Figure 2As shown, the dual-channel high-speed real-time acquisition module includes a high-performance central processing unit, a dual-channel trigger pulse delay unit, a dual-channel high-dynamic AD acquisition unit, and a multi-channel high-precision clock synchronization unit.

[0027] The central processing unit (CPU) receives control commands and transmits collected data to the outside world through the network. According to the parameter configuration, one CPU is set to the master working mode and the other CPUs are set to the slave working mode. The CPU in the master working mode generates the working timing of the entire sampling device according to the set working parameters (including the number of channels) and outputs a synchronization trigger signal to one of the CPUs in the slave working mode. The synchronization trigger signal is passed sequentially among the CPUs in the slave working mode.

[0028] The central processing unit controls the working repetition frequency of its dual-channel high-speed real-time acquisition module, outputs dual-channel transmit trigger pulses to dual-channel trigger pulse delay units, controls dual-channel high-dynamic AD acquisition units to acquire echo signals in a time-division manner, splices, superimposes, filters, and packages the acquired echo signals for external transmission.

[0029] The high-performance central processing unit is a powerful FPGA processor.

[0030] For example, the display and control software configures the dual-channel high-speed real-time acquisition module 1 to be in master mode, while the remaining dual-channel high-speed real-time acquisition modules 2, ..., N are set to slave mode. Dual-channel high-speed real-time acquisition module 1 generates the operating timing sequence of the entire sampling device based on the configured number of modules, completing data acquisition from all transceiver antennas and ensuring time-division multiplexing of different antennas across different modules. Dual-channel high-speed real-time acquisition modules 2 through N sequentially acquire data from their respective two transceiver antennas under the control of a synchronous trigger signal, while simultaneously transmitting the clock and synchronization signals from the previous stage to the next stage module.

[0031] Each dual-channel high-speed real-time acquisition module is configured with a different IP address on the same network segment. All data is uploaded to the display and control software via network communication. Each module's data has a unique identifier to distinguish different channel numbers and acquisition locations. Data from different dual-channel high-speed real-time acquisition modules triggered by the same synchronization signal are combined using the same data number.

[0032] The dual-path trigger pulse delay unit performs precise and uniform step delay scanning of the dual-path transmit trigger pulses, and after shaping and amplification by the pulse forming circuit, outputs them to the transmit antenna of the dual-transmit and dual-receive antenna unit equipped in the dual-path high-speed real-time acquisition module.

[0033] The dual-channel trigger pulse delay unit can generate a minimum 5ps dual-channel sweep frequency transmission trigger signal, and the central processing unit controls the selection of the dual signals.

[0034] The dual-channel high-dynamic AD acquisition unit acquires two analog signals in real time from the receiving antenna of the dual-transmitter dual-receiver antenna unit equipped in its dual-channel high-speed real-time acquisition module.

[0035] The dual-channel high-dynamic AD acquisition unit has a sampling rate of up to 2.5 GSPS and a minimum of 160 MSPS. To ensure the dynamic range of the acquired signal, the sampling bit depth is 16 bits. It is equipped with a low-noise figure op-amp and can be adapted to antennas of different frequencies.

[0036] The multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module in the main working mode central processing unit generates a clock synchronization signal and outputs a clock synchronization signal to a multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module in the slave working mode central processing unit. The clock synchronization signal is passed sequentially between the multi-channel high-precision clock synchronization units of the dual-channel high-speed real-time acquisition module in the slave working mode central processing unit. The multi-channel high-precision clock synchronization unit in the main working mode is a high-performance crystal clock, and the clock source of the multi-channel high-precision clock synchronization unit in the slave working mode is the clock synchronization signal. The high-performance central processing unit controls the selection of the clock source according to the configuration parameters.

[0037] The multi-channel high-precision clock synchronization unit transmits the clock synchronization signal to the central processing unit, dual-channel trigger pulse delay unit, and dual-channel high-dynamic AD acquisition unit of the dual-channel high-speed real-time acquisition module to which it belongs. The central processing unit uses the clock synchronization signal as the timing control clock, the dual-channel trigger pulse delay unit uses the clock synchronization signal as the step delay clock, and the dual-channel high-dynamic AD acquisition unit uses the clock synchronization signal as the AD acquisition clock.

[0038] The four clocks—AD acquisition clock, timing control clock, step delay clock, and the next-level synchronous output clock (clock synchronization signal)—are from the same source and in phase, achieving phase synchronization of multiple clock signals.

[0039] In summary, the sampling device disclosed in this embodiment utilizes high-speed quasi-real-time sampling technology. Through software parameter configuration and multi-channel timing control technology, multiple identical dual-channel high-speed real-time acquisition modules are cascaded and combined into a high-speed three-dimensional array ground-penetrating radar system with any number of channels required for actual scenarios, thus meeting the application needs of different scenarios. Ground-penetrating radar based on high-speed real-time sampling technology can significantly reduce the number of repeated transmissions and increase the operating speed to 60-80 km / h, greatly improving operational efficiency.

[0040] This embodiment also discloses a sampling method applicable to the above-mentioned sampling device. The central processing unit in the main working mode generates a synchronous trigger signal based on the trigger pulse of the ranging wheel and transmits it sequentially to the central processing unit in the slave working mode. Based on this synchronous trigger signal, the echo data and synchronous GPS data of all dual-channel high-speed real-time acquisition modules are acquired. Each dual-channel high-speed real-time acquisition module generates a transmit trigger pulse and a receive trigger pulse in sequence. After traversing all transmit channels, the transmit trigger pulse is delayed by ΔT and then all transmit channels are traversed sequentially until the equivalent number of sampling times is completed, and the real-time sampling data of all transmit channels is acquired.

[0041] by Figure 3 (One transmitter, two receivers, sixteen channels) is used as an example to illustrate the specific working sequence of the sampling method:

[0042] Module 1 operates as the master module, while modules 2 and 3 operate as slave modules. The high-performance central processing unit in module 1 generates a synchronization pulse (SYN) based on the ranging wheel trigger pulse and sequentially transmits it to modules 2 and 3. This pulse serves as the reference for acquiring echo data and synchronized GPS data from all modules. The three modules sequentially generate transmit and receive trigger pulses in a fixed order: Module 1, Module 2, Module 3. After traversing all six transmit channels, the transmit trigger pulse is delayed by ΔT before retracing all channels until the equivalent sampling count is completed, at which point the near-real-time sampling data for all channels is acquired. Following a one-transmit, two-receive design, the two adjacent receiving antennas can simultaneously acquire data.

[0043] exist Figure 3In this diagram, the synchronization pulse for each module is SYN. ​​The transmit trigger pulses for module 1 are R12 and R2, and the receive trigger pulses are R12 and R2, respectively. R12 indicates that when transmit antenna 1 transmits, both receive antennas simultaneously receive the acquired data; R2 indicates that when transmit antenna 2 transmits, receive antenna 2 receives the acquired data. Similarly, the transmit trigger pulses for module 2 are R12 and R2, and the receive trigger pulses are R1, R12, and R2, respectively. R1 indicates that when transmit antenna 2 of module 1 transmits, receive antenna 1 receives the acquired data, corresponding to the R2 receive trigger pulse in module 1. R12 indicates... When transmitting antenna 1 of this module transmits, both receiving antennas simultaneously receive the acquired data. R2 indicates that when transmitting antenna 2 of this module transmits, receiving antenna 2 receives the acquired data. The transmit trigger pulses of module 3 are R12 and R2 in sequence, and the receive trigger pulses are R1, R12, and R2 in sequence. R1 indicates that when transmitting antenna 2 of module 2 transmits, receiving antenna 1 receives the acquired data, and corresponds to the R2 receive trigger pulse in module 2. R12 indicates that when transmitting antenna 1 of this module transmits, both receiving antennas simultaneously receive the acquired data, and R2 indicates that when transmitting antenna 2 of this module transmits, receiving antenna 2 receives the acquired data. The first cycle of transmit trigger pulses for each module channel has a zero delay. The second cycle of transmit trigger pulses has a delay of ΔT, until the last cycle of transmit trigger pulses has a delay of (N-1)*ΔT. The transmit trigger interval for each channel of each module is Tr, and the transmit interval between adjacent channels is Tr / 6. Module 1 acquires 3 channels of data, and modules 2 and 3 each acquire 4 channels of data, for a total of 11 channels of data.

Claims

1. A cascaded multi-channel ground-penetrating radar high-speed real-time sampling device, characterized in that: It includes two or more dual-channel high-speed real-time acquisition modules. Each dual-channel high-speed real-time acquisition module is equipped with a dual-transmit and dual-receive antenna unit. Clock synchronization signals and synchronization trigger signals are cascaded between each dual-channel high-speed real-time acquisition module. Each dual-channel high-speed real-time acquisition module is connected to a router through a network.

2. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 1, characterized in that: The dual-channel high-speed real-time acquisition module includes a central processing unit, a dual-channel trigger pulse delay unit, a dual-channel high-dynamic AD acquisition unit, and a multi-channel high-precision clock synchronization unit.

3. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The central processing unit (CPU) receives control commands and transmits collected data to the outside world through the network. One CPU is set to master mode and the other CPUs are set to slave mode. The CPU in master mode generates the working timing of the entire sampling device and outputs a synchronization trigger signal to one of the CPUs in slave mode. The synchronization trigger signal is passed sequentially among the CPUs in slave mode. The central processing unit controls the working repetition frequency of its dual-channel high-speed real-time acquisition module, outputs dual-channel transmit trigger pulses to dual-channel trigger pulse delay units, controls dual-channel high-dynamic AD acquisition units to acquire echo signals in a time-division manner, splices, superimposes, filters, and packages the acquired echo signals for external transmission.

4. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The central processing unit is an FPGA processor.

5. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The dual-path trigger pulse delay unit performs step-delay scanning and shaping amplification on the dual-path transmit trigger pulses and outputs them to the transmit antenna of the dual-transmit dual-receive antenna unit equipped in its dual-path high-speed real-time acquisition module.

6. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The dual-channel trigger pulse delay unit can generate a minimum 5ps dual-channel sweep frequency transmission trigger signal.

7. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The dual-channel high-dynamic AD acquisition unit acquires two analog signals in real time from the receiving antenna of the dual-transmitter dual-receiver antenna unit equipped in its dual-channel high-speed real-time acquisition module.

8. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 2, characterized in that: The dual-channel high-dynamic AD acquisition unit has a sampling rate of up to 2.5 GSPS and a minimum of 160 MSPS, with a sampling bit depth of 16 bits.

9. The cascaded multi-channel ground-penetrating radar high-speed real-time sampling device according to claim 3, characterized in that: The multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module where the main working mode central processing unit is located generates a clock synchronization signal and outputs a clock synchronization signal to a multi-channel high-precision clock synchronization unit of the dual-channel high-speed real-time acquisition module where the slave working mode central processing unit is located. The clock synchronization signal is passed sequentially between the multi-channel high-precision clock synchronization units of the dual-channel high-speed real-time acquisition module where the slave working mode central processing unit is located. The multi-channel high-precision clock synchronization unit transmits the clock synchronization signal to the central processing unit, dual-channel trigger pulse delay unit, and dual-channel high-dynamic AD acquisition unit of the dual-channel high-speed real-time acquisition module to which it is located.

10. A sampling method applicable to the sampling device of claim 3, characterized in that: The central processing unit in the main working mode generates a synchronous trigger signal based on the trigger pulse of the ranging wheel, and transmits it sequentially to the central processing unit in the slave working mode. Based on this synchronous trigger signal, the echo data and synchronous GPS data of all dual-channel high-speed real-time acquisition modules are acquired. Each dual-channel high-speed real-time acquisition module generates a transmit trigger pulse and a receive trigger pulse in sequence. After traversing all transmit channels, the transmit trigger pulse is delayed by ΔT and then traverses all transmit channels in sequence until the equivalent number of samplings is completed, and the real-time sampling data of all transmit channels is acquired.

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